A Guide to Legal Vehicle Modifications in South Dakota

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If you live in South Dakota or plan to live there in the near future, you need to know the laws governing vehicle modifications. Understanding and complying with the following laws will help ensure that your vehicle is legal when driving on South Dakota roads. Failure to comply with these standards may be considered a Class 1 or Class 2 offense with a fine of between $500 and $1,000 and/or imprisonment of 30 days to 1 year.

Sounds and noise

South Dakota places limits on the amount of sound vehicles can make.

Sound systems

There are no specific rules for sound systems in South Dakota. However, it is illegal to cause annoyance, inconvenience or alarm due to excessive noise levels. However, these levels are subjective and not clearly defined.

Muffler

• Silencers are required on all vehicles and should prevent unusual or excessive noise.
• Vehicles with exhaust pipes are not allowed on the motorway.

FunctionsA: Always check with your local South Dakota County laws to ensure you are complying with any municipal noise ordinances, which may be stricter than state laws.

Frame and suspension

South Dakota does not limit frame height, suspension lift, or bumper height. However, vehicles cannot exceed 14 feet in height.

ENGINES

South Dakota has no engine modification or replacement regulations, and no emission testing is required.

Lighting and windows

Lanterns

• License plates at the rear of vehicles must be illuminated with white light.

• Red, blue and green lights are only allowed on authorized vehicles, not passenger cars.

• One spotlight is allowed that does not hit the road surface more than 100 feet in front of the vehicle.

• Amber flashing lights are allowed within three inches of license plates for disabled drivers. These lamps may only be used if the disabled driver is the person driving the vehicle.

Window tinting

• Non-reflective tinting is permitted on the windshield above the manufacturer's AS-1 line or to the bottom of the sun visor when it is lowered.

• Mirror and metallic/reflective shades are not allowed.

• Front side windows must let in more than 35% of the light.

• Rear side and rear windows must let in more than 20% of the light.

• Each tinted glass requires a sticker between the glass and the film indicating the permitted tint levels.

Vintage/classic car modifications

South Dakota offers historic license plates that meet the following requirements:

• Vehicle must be over 30 years old
• Vehicle must not be used for everyday or normal driving
• Exhibitions, parades, displays and trips for repairs or refueling are allowed.
• Application required for special South Dakota license plate

If you want to make sure your vehicle complies with South Dakota laws, AvtoTachki can provide mobile mechanics to help you install new parts. You can also ask our mechanics what modifications are best for your vehicle using our free online Ask a Mechanic Q&A system.