hi, im doing something similar, but with a different approach. im using an arduino to trigger the mosfets on the the RC car(instead of the regular RX2c IC) and the arduino has a bluetooth module which connects to a phone mounted on the car. the phone receives Arrow key presses from the computer and the phone sends back live video from the phone. then the phone sends the key press data to the arduino which triggers the motors.
i don't know much about the wishield, but in general arduino is very easy to program, to me at least. my sig has a link to my blog which details how to interface a arduino with the car.