Maybe it should be called robo-car, or whatever. I don't know. The only thing I know is that I bought a normal radio-controlled Nikko Scarab at the local toy shop, and then begun connecting it to my Atmel STK500 devboard.
I had it running for a while, with the AVR now controlling the radio transmitter and getting the car to drive around in the house. But what I really want to do, is to get the AVR in the car and control it from there.
So, I have to add some batteries for the AVR and some detection mechanism - the car should know when an obstacle is closing in, and avoid it.
These are my plans. Some day it will become reality. There are already a lot of people building these things, it's not hard. For me it's more a matter of motivation.