Complete Guide to Vehicle Modification Laws in Maryland
Maryland enforces a detailed set of equipment and modification rules covering everything from ride height to underglow lighting. This guide breaks down what's allowed, what's restricted, and what's outright banned for vehicle enthusiasts modifying their rides in the Free State. The figures below were verified against primary statute text (August 2026), so you can rely on them as a starting point before you start wrenching.
Lowering
Status: Conditional
Maryland doesn't set a minimum ride height, so you're free to lower your vehicle as far as you'd like from a suspension standpoint. However, the catch comes at inspection: your bumper cannot be modified or extended up or down to compensate for the suspension or body change. The bumper max for passenger vehicles is 20 in (Class A), and bumpers must stay at full width and unmodified. In short — lower the car, but leave the bumper alone. This falls under COMAR 11.14.02.07. See the full lowering laws page for details.
Aftermarket Exhaust
Status: Conditional
Swapping your exhaust system is legal in Maryland, but a few conditions apply. A muffler in good working order is required, and cutouts are prohibited. Bypasses aren't allowed either. Federal law also prohibits removal of the catalytic converter. Exceptions and exemptions reiterate that your setup must not exceed noise limits, must retain a muffler, must avoid straight pipes or cutouts, and must keep the catalytic converter intact. This is governed by Md. Transp. § 22-402 (see also § 22-601). Check the aftermarket exhaust laws page for the full rule text.
Headlight & Taillight Tint
Status: Illegal
This one's a hard no in Maryland. Smoked or tinted film on headlights and taillights is illegal — no film is permitted at all. Headlights must emit white light, and taillights must show red. Maryland's statute prohibits any tinting, coating, or covering on headlights and taillights that reduces light output or visibility. This is codified under Md. Transp. § 22-204. For more detail, visit the headlight tint laws page.
Light Bars & LED Lighting
Status: Conditional
Maryland allows a specific lighting setup: one spot lamp, two fog lamps, and two auxiliary driving lamps. There's no cover requirement for any of these. The spot lamp must be aimed no more than 100 ft and not left of the vehicle. Fog lamps must sit between 12-30 in, and auxiliary driving lamps between 16-42 in. Where any of these lamps exceed 300 candlepower, a maximum of 4 lit front lamps applies. This falls under Md. Transp. § 22-217. See the light bars laws page for the complete breakdown.
License Plate Frames
Status: Conditional
License plate frames themselves are allowed in Maryland, but nothing required on the plate can be hidden — that means all plate information (numbers, letters, and registration stickers) must remain visible. Notably, all license plate covers are banned, including clear ones. Frames are fine as long as they don't obscure anything. This is covered under Md. Transp. §§ 13-411 and 13-411.1. Full details are on the license plate frames laws page.
Window Banners
Status: Conditional
Maryland treats window banners as an extension of the tint rules. Tinting (and by extension, any material) may not extend below the AS-1 line or below 5 inches from the top, whichever applies — meaning a strip above that line is allowed. But since the material must be transparent, a printed or opaque banner is not legal; only a clear tint band qualifies. Exceptions note the banner must stay within the top 5 inches of the windshield (or above the AS1 line if marked), and it can't obstruct the driver's view of the road or traffic control devices. This is governed by Md. Transp. § 22-406. Visit the window banners laws page for more.
Lift Kits
Status: Conditional
Lifted vehicles are permitted in Maryland, but bumper height caps apply: 20 in for Class A passenger vehicles and 28 in for Class E light trucks and Class M multipurpose vehicles. As with lowering, Maryland specifically rejects bumpers that have been modified or extended up or down to compensate for suspension or body alterations. This falls under COMAR 11.14.02.07. Head to the lift kits laws page for the full rule.
Exhaust Noise
Status: Conditional
Maryland sets numeric decibel limits for vehicles up to 10,000 lb, measured at 50 feet: 78 dB(A) in zones posted 45 mph or less, and 82 dB(A) above that. There's also a stationary test limit of 100 dB(A) at 3 feet from the exhaust, applicable to vehicles built after January 1, 1988. These limits are set under Md. Transp. §§ 22-601, 22-602 and COMAR 11.14.07.04. See the exhaust noise laws page for specifics.
Wheel & Tire Protrusion
Status: Conditional
Maryland tests fender coverage geometrically at inspection. Fenders must extend outward far enough to cover the top of the wheel and tire. Rear fenders must reach down to the wheel's horizontal centerline, and front fenders must extend forward within 45 degrees of that centerline. This is covered under COMAR 11.14.02.08, with truck-specific rules under Md. Transp. § 22-413. Full details are on the wheel protrusion laws page.
Window Tint
Status: Conditional
For standard passenger vehicles, Maryland requires a minimum of 35% VLT on front side windows, and a minimum of 35% VLT on rear side and back windows. Darker limits may apply behind the driver on some larger vehicles.
Differs by vehicle: For SUVs, trucks, and vans, front side windows still require a minimum of 35% VLT, but on these multipurpose vehicles, only the driver-adjacent windows are regulated — windows behind the driver are unrestricted.
This is governed by Md. Transp. Code § 22-406. Check the window tint laws page for the full breakdown by vehicle type.
Underglow
Status: Conditional
Underglow lighting is legal in Maryland, including while driving, but with strict color and behavior limits. Lighting must stay steady — oscillating, rotating, and blinking lights are banned unless authorized. Red and blue are reserved for emergency vehicles, white or amber is permitted to the front, and no white is allowed to the rear. Exceptions clarify that underglow lights cannot be red or blue, cannot be visible while driving on public roads in violation of these rules, and cannot flash or strobe — with white and amber generally the only permitted auxiliary colors. This falls under Md. Transp. § 22-218. See the underglow laws page for more.
Every modification above links to its full law page with exact limits, statute citations, and exceptions — or browse every Maryland mod law in one place, free.
Disclaimer: This guide is for informational purposes only. Data is AI-extracted from public statutes and may contain errors. Always verify with local authorities.