Originally Posted by ThoughtCriminal

Just a n00b suggestion, but why dont get one of those electric kid cars? Grab a reciprocating saw and cut off everything but the frame. You can extend it to fit the length, and run a sevo to the speed control, and steering.

You can find those cars used at the flea markets/junk shops for under $20. Throw a 12v lawnmower battery in it, and it will cook right along.