Complete Guide to Vehicle Modification Laws in Wyoming
Wyoming's open roads and rugged terrain make it a popular state for truck builds, lifted rigs, and custom rides — but that doesn't mean anything goes. This guide breaks down the state's key vehicle modification laws so you know what's legal, what's conditional, and what will get you a ticket. The figures below were verified against primary statute text (September 2026), so you can treat them as accurate as of that date. As always, laws can change, so double-check before you make a major investment in a build.
Exhaust Noise
Status: Conditional
Wyoming doesn't set a statewide decibel limit for passenger cars — there's no specific number to hit or stay under. Instead, the law requires a muffler in good working order, prohibits exhaust that produces excessive or unusual noise, and bans cutouts or bypasses outright. This gives some flexibility for aftermarket setups, but "loud for the sake of loud" can still run afoul of the excessive-noise standard. See the full exhaust noise laws for details. This is governed under Wyo. Stat. § 31-5-953.
Window Tint
Status: Conditional
Wyoming's tint law sets a minimum of 28% VLT across the board: front side windows, rear side windows, and the back window all require at least 28% VLT. There's also an allowance for darker limits behind the driver on some larger vehicles. Specifically, SUVs, trucks, and vans must meet the same 28% VLT minimum on front side windows, but trucks, buses, limousines, and MPVs are exempt from tint restrictions behind the driver. This falls under Wyo. Stat. § 31-5-962. Full details are on the window tint laws page.
Underglow
Status: Conditional
Wyoming has no underglow-specific statute, so underglow setups are judged against the state's general lighting rules. No red or blue light may be visible from directly in front of the vehicle on non-emergency vehicles, and rear-mounted devices must show red. Flashing lights are prohibited except for statutorily authorized vehicle classes — emergency, school bus, construction, wreckers, utility, and similar vehicles. On the aiming side, any non-headlamp device over 300 candlepower must not strike the roadway beyond 75 ft. Check the underglow laws page for the specifics. This is covered under Wyo. Stat. §§ 31-5-928, 31-5-917.
Light Bars & LED Lighting
Status: Conditional
Wyoming doesn't require a cover on light bars or auxiliary LED lighting, but it does cap how many can be lit at once: no more than 4 front lamps may be lit at one time on a highway. Non-exempt lamps over 300 candlepower must not strike the roadway beyond 75 ft, though spot and auxiliary lamps are excepted from that aiming rule. See the light bars & LED lighting laws page for more. This is addressed under W.S. §§ 31-5-927, 31-5-928.
Aftermarket Exhaust
Status: Conditional
Swapping out your factory exhaust system is legal in Wyoming, but a few rules apply. The system must include a muffler in good working order, and straight pipes, cutouts, and bypasses are prohibited. Wyoming doesn't have a strict "no louder than stock" rule on the books — instead, the standard is that modifications can't push noise beyond excessive or unusual levels. Catalytic converters are required on vehicles originally equipped with them, and removing one is prohibited under federal law regardless of state statute. Full specifics live on the aftermarket exhaust laws page. This falls under W.S. § 31-5-953.
Lift Kits
Status: Legal
Good news for truck and off-road enthusiasts: Wyoming sets no statewide lift, frame-height, or bumper-height limit. The only real ceiling is the state's overall vehicle height cap of 14 feet. Beyond that, general equipment rules — like proper headlamp height and functioning lighting — still apply to lifted vehicles. See the lift kit laws page for more. This is governed under Wyo. Stat. § 31-18-802.
Lowering
Status: Legal
On the flip side, Wyoming has no statute dictating how low a vehicle can be lowered. That said, general equipment requirements still apply — headlamp height, working lighting, and making sure nothing drags on the road are all still enforceable regardless of ride height. Learn more on the lowering laws page.
Headlight & Taillight Tint
Status: Illegal
Smoked or tinted film on headlights and taillights is not permitted in Wyoming. Headlights are required to emit white light and taillights must show red at the required visibility distance — film that dims or discolors either one violates those color and visibility requirements. Film is simply not permitted on these lights. More details are on the headlight & taillight tint laws page. This is covered under W.S. §§ 31-5-910, 31-5-912, 31-5-913, 31-5-928.
Wheel & Tire Protrusion
Status: Legal
Wyoming has no fender, mudguard, mud-flap, or splash-guard requirement, and there's no limit on how far tires may protrude. This gives builders significant flexibility with wheel and tire fitment compared to states with strict fender coverage rules. See the wheel & tire protrusion laws page for more.
Window Banners
Status: Conditional
Wyoming allows a sunscreening device only along the top of the windshield, and it can't extend below the AS-1 line or more than 5 inches from the top — whichever point is closer to the top. Because the material used must be transparent, a printed or opaque banner doesn't meet the legal standard here; only a clear tint strip along the top of the windshield is allowed. Full details are on the window banners laws page. This falls under W.S. § 31-5-962.
License Plate Frames
Status: Conditional
License plate frames are legal in Wyoming as long as they don't obscure anything on the plate. State law requires plates to be conspicuously displayed, securely fastened, plainly visible, secured against swinging, positioned at least 12 inches from the ground, and kept free from foreign materials. Plate covers count as a "foreign material" and are not permitted, and the whole plate must remain visible at all times. See the license plate frame laws page for specifics. This is governed under Wyo. Stat. § 31-2-205(a)(i)–(iv).
Every modification above links to its full law page with exact limits, statute citations, and exceptions — or browse every Wyoming mod law in one place, free.
This guide is for informational purposes only. Data is AI-extracted from public statutes and may contain errors. Always verify with local authorities.