Top Car Mods That Are Illegal in Certain U.S. States

Many popular vehicle modifications violate state laws, with window tint, exhaust systems, and suspension alterations being the most commonly banned. California leads with the strictest regulations, while Texas and Florida have surprising prohibitions that catch many car enthusiasts off guard.

In 2024, the most frequently ticketed modifications include window tint darker than 35% VLT (illegal in many states), exhaust systems exceeding 95 decibels (banned in California and New York), and suspension lifts exceeding 4 inches (prohibited in several states). Fines for these violations range from $100 for first offenses up to $1,000 for repeat violations in strict states.

Most Commonly Banned Modifications by State

California: Aftermarket exhausts, ECU tuning, certain cold air intakes
Texas: Red/blue underglow lighting, certain bumper heights
New York: Window tint on front side windows, exhaust modifications
Florida: Certain wheel protrusions, altered suspension geometry
Pennsylvania: Colored headlights, certain frame modifications

Surprisingly Illegal Mods Many Don't Know About

- License Plate Frames: Illegal if covering any text in 15 states
- Neon Underglow: Completely banned in 9 states, restricted in others
- Hood Scoops: Illegal if over 4" tall in several states
- Side Mirrors: Required on both sides in most states regardless of cameras
- Weight Reduction: Removing factory seats illegal in some states

How to Modify Your Car Legally

Research State Laws: Check DMV websites for equipment regulations
Get Professional Installation: Certified shops know legal limits
Keep OEM Parts: Swap back for inspections if needed
Check Local Ordinances: Some cities have additional restrictions
Consider "Off-Road Only": Some parts legal if not driven on public roads