Is an underglow light kit legal for car enthusiasts in Montana in 2026? Yes, but only if it meets specific state requirements. Under Montana Code Annotated § 61‑7‑203, colored lighting that is not white, amber, or red must be permanently disabled while the vehicle is in motion unless the vehicle is a show car or is operated on private property. In 2025 the legislature introduced a clarification allowing a detachable switch to turn the underglow off when driving on public roads. Failure to comply can result in a fine of up to $300 and possible citation.
Current Legal Status
Montana treats underglow as “auxiliary lighting.” The law permits such lights if they are off while the vehicle is being driven on public highways. A permanent wiring modification that disables the lights automatically when the ignition is on satisfies the requirement. Show vehicles displayed at sanctioned events are exempt, provided the lights remain off during transit to and from the venue. Violations are recorded under MVD Code § 61‑7‑203, which authorizes a traffic stop and citation.
Recent Legislative Activity
In the 2025 session, lawmakers introduced HB 542 to address the growing popularity of LED underglow among younger drivers. The bill did not legalize continuous use but added a provision that a quick‑release switch installed within arm’s reach is deemed “permanently disabled” for enforcement purposes. The amendment passed with bipartisan support and took effect on January 1, 2026. No further changes have been proposed for 2026, so the current framework remains in force.
Practical Compliance Tips
- Install a manual switch within the driver’s reach that cuts power to the underglow when the vehicle is moving. A relay tied to the ignition is the most reliable method.
- Label the switch with a clear “OFF while driving” notice to avoid confusion during police stops.
- Use only white, amber, or red lights on the front and rear if you want continuous illumination without a switch.
- Keep documentation of the installation, including photographs of the switch and wiring diagram, in case you are cited.
- Participate in recognized car shows; the exemption applies when the vehicle is transported to the event with the lights off.
Key Takeaways
Underglow is not outright banned in Montana, but the law demands it be disabled while the vehicle is on public roads. The 2025 amendment gives enthusiasts a practical solution—a quick‑release switch—provided it is operational and easily accessible. Compliance is straightforward: install a manual cut‑off, keep records, and respect the off‑while‑driving rule. Failure to do so can lead to fines and citations, but with proper setup most car lovers can enjoy their lighting safely and legally.
Can I use underglow on a daily driver?
Only if the lights are turned off via a manual switch while the vehicle is moving on public roads. Otherwise, the vehicle is subject to citation.
Are there color restrictions for underglow?
The law does not restrict colors that are turned off while driving, but any permanently illuminated color other than white, amber, or red is prohibited on public highways.
Do show cars get a permanent exemption?
Show cars are exempt only during the event and while being towed or transported to the venue. The lights must still be off during any public‑road travel.
What penalty applies for a violation?
A first‑offense citation can carry a fine of up to $300, plus possible points on the driver’s record under Montana Vehicle Code § 61‑7‑203.
Is a remote‑control system acceptable instead of a manual switch?
The statute requires a “permanent disabling mechanism” that is within the driver’s immediate control. A remote that can be engaged from a distance is not considered compliant.