Check out this great RC Van project that runs on pi, from seeourfamilytravels:
It’s taken some time and research, but I have finally (well almost, just a few tweaks needed) finished my RasPiVan project. The plan, build an rc vehicle with a Raspberry Pi at it’s heart and here it is, using a mini keyboard for control, via Scratch GPIO, Lego Technic motor for drive, leds and sensors all connected to the Raspberry Pi, via the 4Tronix PiRoCon Raspberry Pi addon board.