My advice
1. Try to get hands on a remote controled toy car and then interface teh remote using a ckt to the PC. Tho this wont be a real project but a make-do
2. Search google using - R/c circuit cars,electronic interface serial port,servo motors, etc...
here are a few basics
Toy Car Tx/Rx 27MHz - Tx/Rx means transmitter/reciever
A R/C Switch - R/C means remote controlled
Simplest R/C Circuit - very simple R/c switch(u will need a array of R/c switches to control stuff
these are a lot to start with and quite hard to find on the net. So i wont search more now. if u really want to do this project then post details of ur porject here and then i will try and help.