Today’s invention is a set of light, transparent, hollow panels corresponding to the body panels of a particular car.
To the narrow space within each is attached an inlet pipe at the front edge and an outlet pipe from the rear edge. These are used to pump smoke through the narrow space from a central reservoir.
The smoke can be made to change colour rapidly (as happens with eg a distress flare or firework). This provides something close to programmable colouration for the vehicle.
Streaklines in the smoke flow can also create the illusion that the vehicle is travelling faster than it really is, thus adding drama to driving slowly and perhaps reducing accidents.