If you’re talking about plastic CIK-style bodywork, you’re going to have a tough time getting paint to stick and any contact you make with other karts is going to mess the paint up pretty quickly.
A decal wrap will be cheaper, look better, be more durable, and easier to fix. Rubber marks can be cleaned off decals relatively easy or you can just peel the decal off and apply a new one. Paint is a much much bigger pain to touch-up. Not worth the time.
If you’re talking 4-stroke fiberglass bodywork, it’s more feasible but still you run into the same issues with touching it up and the paint getting ruined relatively easily compared to decals.