Seems that using DPDT relays is the easiest approach to get this car on the road -er gym.

Parallax has been suggested.

If I go with Parallax I need:

BASIC Stamp 2e Module $54.00
either:
BASIC Stamp 2pe Motherboard $70.00
or
Board of Education (USB) - Full Kit $100.00

From TYCO or, 2 AXICOM V23105 dpdt DC relay ~$5.00 each

Maybe some parts from Radio Shack like 7.5 volt power supply and a USB cable.

What else besides my RC car a work bench and some time?

Ken