These Car Modifications Are Illegal In The US

These Car Modifications Are Illegal In The US

The Fast and the Furious isn’t just one of the most exciting film franchises of all time, but it also introduced the weird and wonderful world of car modifications to the larger American public, most of whom thought that “car modifications” meant adding a bumper sticker.

Updated July 2021: If you’re planning to modify and customize your car, you’ll be happy to know we’ve updated this article with some more laws and regulations regarding what you can and cannot do. These laws differ from state to state, so they may or may not apply to your particular build.

Many thousands of young men and women spend countless dollars on upgrades and modifications on their vehicles in order to improve how they look,perform, or even sound before parading them at meets and races with other car enthusiasts.

The global market for car modifications is worth hundreds of billions of dollars and isn’t showing any signs of slowing down as more and more people look to put their own personal stamp on their vehicles. It is worth remembering that it isn’t just the cost of the modification that you have to take into consideration, as some of these embellishments can actually increase the cost of your auto insurance premium!

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For various reasons, some of the most popular modifications are also very illegal. Just to make things even more complicated, different states have different rules about which modifications are allowed, so you always need to check the rules relating to the modifications on the list below before you go on any cross-country road trips. Here are some car modifications that are illegal in the United States.

Light Rig On The Roof Of A Truck


A lot of people who own trucks also like to pretend that they use those trucks for journeys far more demanding than the school run or the morning commute. We’ve all seen truck drivers who have spent as much cash upgrading their pride and joy as any Fast and Furious-inspired street racer.

Related: Opinion: Here’s Why You Should Care About The RPM Act

One of the staunch favorites of truck owners is a light rig on the roof in order to provide extra bright illumination for those after dark off-roading trips. It is worth noting that some states have restrictions about the use or even the installation of such lighting rigs. In 2017, for example, North Carolina passed a law prohibiting the use of these rigs while driving on state highways, as they can distract and even blind other road users.

Related: Modified Off-Road Lamborghini Drives To Unlikely Destination For Its First Test Drive

Radar Detectors, Radar, And Laser Jammers


Radar detectors are devices that will inform drivers when their speed is being measured by radar guns used by law enforcement; a handy toy if you like driving above the speed limit without the risk of being given one of those pesky traffic citations. That is why these are illegal in all vehicles in Virginia and Washington DC, and are illegal in commercial vehicles in Illinois, New York, and New Jersey. While radar detectors are legal in Minnesota and California, you are not allowed to fix them to your windscreen, where they may cause obstruction while driving.

Radar and laser jammers go one step further and actually block signals emitted by police devices so that they can’t even register your speed in the first place. Radar jammers are illegal under federal law because of FCC regulations on the use of unregulated radio signals, and the use of them can lead to a fine or even a prison sentence wherever you live in the U.S. Laser jammers are a bit more of a gray area under federal law, though they have been ruled illegal under state law in California, Colorado, Illinois, Texas, Virginia and Washington DC among others.

Obnoxiously Loud Exhausts


All vehicles are sold with a muffler on their exhaust system to control noise levels. While it is generally illegal to remove them, there are aftermarket exhaust systems out there if you want a more throaty roar. Again, different states have different laws when it comes to how loud your exhaust is allowed to be. Texas, for example, has no vehicle noise rules at all, which means pretty much anything goes when it comes to engine noise.

In California, the limit is 95 decibels while Kansas law states that noise from car engines has to be less than 90 decibels when measured from a distance of 50 feet. Some cities, including New York, even have their own local laws on engine noise. Minnesota state law states that “Every motor vehicle shall at all times be equipped with a muffler in good working order.” Remove it or get one that’s too loud, and you could find yourself breaking the law.

Neon Lights


One of the other popular modifications to make a regular appearance in the Fast and Furious films are neon lights mounted underneath vehicles. While this may look cool, it doesn’t have any impact on the performance of the vehicle, so why on earth would any state have a problem with a bit of extra funky lighting?

In actuality, that extra lighting can be a distraction to yourself and to other drivers. Arizona allows neon lights, but only amber or white lights on the side of the car. Kansas doesn’t allow you to use flashing lights. Michigan also has restrictions on neon lights, with red and blue lights banned altogether. Maybe that’s because other drivers mistake them for the lights on a police car?!

Exhaust Pipes Without Emissions Equipment


The trend these days among most drivers is to drive increasingly environmentally friendly cars. You just have to look at the success of hybrids and EVs to see how attitudes towards pollution that results from motoring is changing. The Environment Protection Agency seems hellbent on banning car mods, so of course, they have rules about what emissions are allowed from the exhaust pipes of engines that still rely on good old fashioned gasoline, yet there are mods on the market which can affect the amount and type of emissions which are expelled from your exhaust and can easily lead you to run afoul of the law.

New cars are all sold with devices that control the emissions from your car but if you want to remove them to change the performance of your vehicle, then you could be open to prosecution under the Clean Air Act.

Lifted Suspension


Making changes to your car’s suspension is one of the more common modifications, whether it’s by increasing or decreasing the distance between your car’s bodywork and the road. Truck owners are particularly keen on lifting the suspension of their vehicles, but this can make the truck difficult to handle and potentially dangerous to use on roads.

If you want to lift your suspension or drive through a different state with a high suspension which is legal at home, check what the local rules are before you make any decisions. Connecticut, for example, only allows vehicle owners to lift their suspension by a maximum of four inches, while in Georgia the limit is a two-inch increase in ground clearance.

Very Low Suspension


There are some car owners who want to lower the suspension of their vehicle to improve its appearance and handling as well as reduce drag so that one can achieve faster speeds. There are certain risks associated with a lower suspension, including the fact that a car could end up getting damaged by the first speed bump one drives over, and some states have restrictions on how low vehicle suspensions can be.

Georgia’s two-inch restriction also applies to lowered suspensions, while in New Hampshire no part of the vehicle’s bodywork or chassis can be lowered so that it lies below the lowest part of the car’s wheels. Who knows why anyone would want parts of the car to be below the wheels though.

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Colored LED Headlight Bulbs


Neons are far from the only light-based modification people can make to their cars. You can even jazz up your headlamps, tail lights, or indicators with LED lights using different colors and effects to make them look more eye-catching. Or can you? As far as the law is concerned, many of the same restrictions often apply to LED highlights as apply to LED neons on the underside of your car.

Kentucky has become one of the most recent states to pass a law banning the use of colored LED bulbs in headlights, not only because they are distracting to other drivers, but because if they are installed incorrectly it can be difficult to control the beam, which can lead to oncoming drivers being blinded by your disco headlights.

Brighter HID Headlights


While you may think that you are being a conscientious road user by installing brighter HID bulbs in your headlamps, you could be pulled over for breaking the law. HID stands for High-Intensity Discharge and gives off a much brighter, bluish-white light. Some drivers think that it helps them to be better drivers at night, but it certainly doesn’t help anyone coming in the other direction if your headlights are too bright!

HID lights don’t comply with federal rules on headlamp bulbs, which state that replacements must match the specification of the original equipment. Aftermarket HID lights work differently from the halogen bulbs the car came with when it first rolled off the production line.

Nitrous Oxide Systems


The Fast and The Furious also introduced nitrous oxide to a whole new audience, with racers using it to give themselves a much-needed boost in street races. Nitrous oxide would seem to be part and parcel of any street racer’s modifications package, but its use is illegal in many parts of the U.S.

Ohio has some of the strictest laws regarding the use of NOS. When you buy nitrous oxide there, you have to sign a form declaring that you know it is illegal to use it in a car. Sellers are also required to keep the names of people who have bought the gas on file for two years after the sale.

Plate Frames


Lots of people like to personalize their vehicles in some way so that it reflects their own style and even their own personality. This can range from getting a new paint job in your favorite color to something as simple as slapping on a bumper sticker to let fellow drivers know how proud you are of your kids or how you voted in the last election.

You can even buy decorative frames to put around your license plate. You would do this to reflect your love of Disney or Star Wars, for example. Who could object to that, right? Most states will tolerate these frames so long as they don’t obscure the state of origin or the number, but North Carolina has banned plate frames altogether for vehicles registered in-state.

Rolling Coal


If the Environmental Protection Agency rules prevent car owners from removing the emissions control devices from their car, then you can be sure that the EPA will definitely frown upon the phenomenon known as rolling coal. This is a modification made by diesel vehicle owners that sees more fuel taken into the engine than necessary so that huge, rolling, black clouds are pumped out the exhaust.

It may look impressive, but environmentally friendly it is not! The EPA has deemed the practice illegal and states such as Illinois, New Jersey, Colorado and Maryland have passed their own laws banning the modification itself from being made and imposing fines on anyone who is caught on the roads belching black diesel smoke from their trucks.

Special Covers For License Plates


While drivers who get punished for using decorative license plate frames might rightly feel aggrieved at being fined for such a simple cosmetic change, the same cannot be said for those drivers who very deliberately use special covers for their license plates in a bid to beat speed cameras as well as those used at bridges and tunnels to charge tolls.

New York City has thousands of cameras and the practice of using plastic covers to deflect light and prevent cameras from reading license plates is also widespread even though it is illegal in the state. In fact, it is so widespread that even NYPD and city employees have been caught using the illegal scam! Most states have laws that say license plates must be fully visible, and any infraction can be punished with a fine.

Extremely Loud Stereo Systems


Loud exhausts aren’t the only car modifications that can break laws designed to control noise pollution. Even with today’s high-end car entertainment systems, many drivers feel that their stereo systems need an upgrade so that they can enjoy their favorite tunes at top volume while they’re driving. Of course, when the volume is turned up to 11 inside the car, then the people outside can also hear it!

Most states have laws against noise pollution, especially in residential neighborhoods at night – though Florida recently dismissed an old law that stated that music was too loud if it could be heard 25 feet away as unconstitutional. There is nothing to stop you from upgrading your car stereo anyway, so long as you are prepared to keep that volume dial turned down when driving through a residential area.

Window Tint That’s Too Dark


Once upon a time, tinted windows were the preserve of celebrities trying to protect themselves from the glare of the paparazzi, but it seems that these days even ordinary citizens demand the protection of tinted windows on our vehicles. While, tinted windows are helpful when the sun is baking, tinting on the rear and side windows can, in many cases be so dark that it poses a safety hazard, especially in bad weather when your visibility is already reduced.

All the states have different limits when it comes to how much tinting can be applied to side and rear windows. If yours are deemed to be too dark, then you could find yourself pulled over by local cops. In Alaska, for example, tinting must allow 70% light transmittance on side windows in the front, and 40% in the rear.

Front Windscreen Tinting


Amazingly, some drivers even seem to think it’s a good idea to have tinting on their windscreens despite the obvious safety hazard. A few inches of tint at the top of the windscreen actually does help drivers by preventing them from being dazzled by low sunlight, but states also have their own rules about whether any windscreen tinting is allowed at all, and if so, what restrictions are applied.

Most states forbid windscreen tinting apart from the top five or sometimes six inches to help with driving in sunlight. In Colorado, Rhode Island, and North Dakota you can tint the whole of your windscreen so long as it allows 70% light transmittance. The only exceptions to this ban are people who have light-sensitive medical conditions.

Related: These Modified Nissans Prove That Stance Can Look Awesome

Cold Air Intake


A cold air intake is an engine modification that can be illegal in California if it doesn’t have the appropriate certification. Any modifications that have an impact on the vehicle’s factory settings emissions levels are forbidden in the Golden State, which takes its commitment to cut pollution and protecting the environment very seriously.

If your cold air intake isn’t stamped with a CARB EO exemption number then you’re breaking the law. If you are determined to get a cold air intake installed in order to increase power and improve your miles-per-gallon stats, you can pay extra for good quality parts, which have been approved by the state as maintaining or even improving the factory standard emissions levels.


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