It works by using a special switchpad to precisely track location of vehicle in wash to spray when the tire is located directly in front of spray nozzle

What keeps the tire dressing from running off the tire?

The Viper tire shine tire dressing is a special formulation designed to be applied to a wet tire. This allows the tire dressing to bond to the rubber as the car moves slowly through the wash.

Do I have to cut my track out to install the unit?

Depending on the type of rail you track has there may need to be holes cut into the side rail in order to allow the spray nozzles access to the sidewall of the tire.

How can I control which vehicles get it and which ones don't?

The Viper Shine unit requires one open relay from the main carwash controller. This relay will serve as the input for tire shine and will be turned on/off as desired.