8 Car Features That Are Illegal in Some States

August 16, 2025

Buying or modifying a car can be a great way to express your style or improve your driving experience. But did you know that some car features are illegal in certain states? Understanding which car features are illegal in some states is important for avoiding fines, failed inspections, or even getting your car impounded. The rules can be confusing and differ widely across the country. Features that are perfectly legal in one state may land you in trouble just a few miles away. Before you buy a new vehicle or make any upgrades, it pays to know the laws in your area. Here are eight car features that can get you in trouble, depending on where you drive.

1. Tinted Windows

Window tinting is a common upgrade, but it’s one of the most regulated car features that are illegal in some states. Most states allow some level of tint, but the allowable darkness and reflectivity vary. For example, California has strict rules about how dark your front side windows can be, while states like Florida are more lenient. If your car’s tint is too dark, you might face fines or be required to remove it. Always check your state’s specific requirements before getting your windows tinted.

2. Radar Detectors

Radar detectors help drivers avoid speeding tickets by alerting them to nearby police radar. However, these devices are banned in Virginia and Washington, D.C. Commercial vehicles are also prohibited from using them nationwide. Some states even outlaw radar jammers, which interfere with police equipment. If you cross state lines with a radar detector, you could be breaking the law without realizing it. It’s smart to check local laws before relying on this technology.

3. Aftermarket Exhaust Systems

Many car enthusiasts upgrade their exhaust systems for better performance or a more aggressive sound. Unfortunately, loud or modified exhaust systems are among the car features that are illegal in some states. California, for example, limits exhaust noise to 95 decibels, and police can issue fines for violations. Other states may have similar restrictions or require emissions testing. If you love a roaring engine, make sure your upgrades are legal where you live or travel.

4. License Plate Covers and Frames

License plate covers and frames might seem harmless, but they can be illegal in some states. Many people use them to protect their plates or add a custom look, but if they obscure any part of the plate or the registration stickers, you could get ticketed. Some states ban tinted covers altogether because they can interfere with red light cameras and law enforcement. Always ensure your license plate is fully visible and unobstructed to avoid unnecessary trouble.

5. Blue or Red Lights

Adding blue or red lights to your vehicle may sound cool, but it’s illegal in many states unless you’re driving an emergency vehicle. The reason is simple: these colors are reserved for police, fire, and ambulance services. Using them on a personal vehicle can confuse other drivers and law enforcement. Even accent lighting in these colors can result in a citation. Stick to legal lighting options to keep your car both safe and street-legal.

6. Underglow Lighting

Underglow or neon lighting is popular with car enthusiasts who want their vehicles to stand out. However, underglow is another car feature that is illegal in some states or comes with strict limitations. Some places ban certain colors, while others prohibit any lights that are visible from the front of the car. States like Michigan and Illinois have specific rules about which lights can be used and how they’re displayed. When in doubt, check your state’s vehicle code before installing underglow lights.

7. Front License Plate Removal

Not all states require a front license plate, but in those that do, removing it can lead to fines. States like Texas, California, and New York mandate both front and rear plates. If you move to a state with different laws or travel across state lines, you could get pulled over for missing a front plate. It’s a small detail that can have big consequences, so always know your state’s requirements.

8. Studded Tires

Studded tires can improve traction on icy roads, but they can also damage pavement. That’s why they’re a car feature that’s illegal in some states or only allowed during certain months. States like Florida and Hawaii ban them completely, while others, including Oregon and Colorado, permit them only in winter. Using studded tires out of season or in a prohibited state could earn you a hefty fine or even require you to swap tires on the spot.

Staying Legal with Your Car Features

Car features that are illegal in some states can turn a fun upgrade into a costly headache. Laws change frequently, and what’s allowed in one state might be banned in the next. Before you make any modifications or drive across state lines, research local rules using resources like the Governors Highway Safety Association or your state’s DMV.

If you’re buying a used car, ask about any modifications and verify they comply with your state’s laws. Responsible upgrades keep you safe, legal, and free from unexpected fines. To learn more about keeping your car compliant, check out this helpful NHTSA equipment guide for more details.

Have you ever run into trouble with a car feature that was legal in one state but not another? Share your story in the comments!

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