In car culture, modifying your vehicle is not just a hobby… for some, it’s a way of life. From the days in the past of popular hot rodding to current import tuning, it’s a passion that has spanned generations. An entire culture and the world of motorsports was born from the unrelenting urge to make our machines faster, louder, and stand out from the crowd. It’s a statement of self-expression, an extension of oneself, a veritable lifestyle.

Clearly, the heyday of hot rodding is a distant memory. As our grandparents would say about its former glory, “those were the days”. The days when such notions as fuel efficiency, environmentally friendly, and even basic safety, were not yet part of our collective zeitgeist.  A time where our machines were unapologetically fast, and proudly loud, with a blatant disregard for the environment and our neighbors’ ears.

Today’s generation of motor enthusiasts is no different. Automotive enthusiasts still burn with the desire and passion to modify their vehicles. Whether it is performance oriented, cosmetic, or both, before spending your money it’s important to know which modifications are generally allowed and which may be prohibited when it comes to current regulations and laws.

Laws And Regulations On Modifying Vehicles In The U.S.

Due to current concerns for the environment and safety, today’s car culture is challenged with the task of staying within the guidelines of today’s laws and regulations when going forward with plans for modifying any vehicle.

In the U.S., laws differ from state to state, so each state adheres to their own set of rules and regulations. Therefore, before you start modifying your vehicle, it’s a good idea to look at common modifications that may be subject to restrictive laws. It is your responsibility to look up the laws in your specific state and city ordinance.

  • Tinted windows

In most states tinted windows are not technically illegal. However, state              to state may differ as to what threshold of tint is considered acceptable. Dark tint, such as limo tint is usually illegal across the board. Typically, you may only tint your rear passenger windows, and your back window. It is illegal to tint your vehicle’s front windows as it may obstruct your view, which is a definite safety concern.

  • Exhaust System

Any modifications that involve emissions are typically illegal throughout the 50 states. States like California, and New York just to name two, will not enable your vehicle to pass smog inspection if your exhaust system is not certified CARB exempt. Aftermarket exhaust components such as headers, and catalytic converters, must be CARB exempt to be able to comply with this requirement.

  • Air Intakes

Changing your air intake system has a direct effect on your vehicle’s emissions. Much like your exhaust system, most states will not enable your vehicle to pass smog if your air intake system has been modified, such as with short ram, or cold air intakes. However, there are certain brands that are exempt from emission regulations. When purchasing an after-market intake system, look out for products that are CARB exempt. These intake systems are designed and approved to not affect your vehicle’s emissions.

  • Vehicle Height

Modifying your vehicle height is not technically illegal, and again, each     state has different guidelines as to what is acceptable and not acceptable. States like Texas for example, tend to be much looser with regulations as far as modifying your vehicle’s height is concerned. It is wise and good practice to check with your local laws before installing any height modifications as your local laws may be quite different from Texas.

  • Suspension

Modifying your suspension with such components as upgraded shocks, coil springs, and control arms, is not illegal.To ensure safety with these modifications, make sure they are installed by a professional mechanic.

  • Bull Bars, or Nudge Bars

Bull bars are currently unregulated in the U.S. However, depending on your state and local ordinance, there are guidelines that must be followed. An example would be the regulation that the bull bar cannot obstruct the view of the vehicle’s license plate. Although bull bars are not technically illegal in the U.S. they are frowned upon. Other countries like India, and the British government, have out right banned them, citing safety concerns. As always, check your local laws before installing any modifications.

  • Light bar

It is not illegal to install a light bar, but it is illegal to drive on the street or highways with them turned on. In most states, leaving them turned off is not enough. While the vehicle is driven on the streets or highway, the light bar must be completely covered at all times.


In conclusion, it bears repeating that before modifying your vehicle, it is your responsibility to check with your state and local laws. Remember these laws and regulations do serve a purpose and are there for your safety and environmental concerns. Even within the regulation constraints, car enthusiasts are dedicated and will find a way to adapt within the regulations. Enjoy your hobby, lifestyle, and choices, but most importantly stay safe, and have fun.