Acrylic sheeting can be painted with water-based paint on latex base or acrylic lacquer. Be sure to use a good primer that is suitable for plastic. The primer ensures that the paint adheres to the surface and doesn't flake or peel. I just used a cheap can of black spray paint and some scraps of acrylic I had on hand. Just like normal car bodies, paint on the inside.
Here is some run footage of the DR10 for your enjoyment.
Running on the street:    • Side Winder  
Running in the dirt:    • DR 10 bashing in the dirt