OtakuSanel built a cool RC car that uses an Arduino, PS3 Controller and a few XBee transmitters. The RC car electronics are totally custom allowing him to take full control of the car functions using his PS3 controller. Range is great since the XBee transmitters are the 60mW units, line of site is claimed to be 1 mile on these things!
You can see some intro videos of the first car build below (smaller car). Video 1, video 2, video 3, video 4.