This is a cool way to remote control your car. The microcontroller is a bit of an older one, have a look at the 16f628 for a more modern one these days. Have a look at the build history to see the beginnings of this intro project.
Via: HG Forum
"I basically took a remote controlled car, and connected it to a 16F84 programmable chip, and now I can control the car using C code."