Level of alteration
The register vehicle can no longer be recognizable as a truck / car / golf cart / lawnmower - meaning throwing a tarp over it does not qualify as an art car. The alteration must be so that it transforms the vehicle into something completely new and creative.
Design your art car with safety in mind, yours and that of other participants who may ride on your vehicle.
Be sure to provide adequate lighting for your art car during the evening to make you visible at all times.
Make plans to follow sound guidelines for your vehicle if you plan on adding sound to it