Decide what purpose you intend to use your remote controlled car for. If you want to make a toy for a kid then things should be kept simple and easy. On the other hand if you want to make it for a science project in your college, you will have to get grist of wireless networking and RC cameras and then interface them properly in order for them to work.
In either case you will have to get a toy car first to be used as a platform in the project. Purchase one from a nearby gift store and find out its working in detail. If the RC controller in the toy car is good enough, you will not have to build one yourself, so buy a high quality remote control car to reduce your work by half.
The difficult part of the project is to interface a workable wireless camera with our RC controlled car. The simplest way to go about this is to use an embedded platform which has ports for the installation of wireless camera modules directly on it. One such board is the beagle board XM.
Beagle board has a 1 GHz process and boasts its own operating software. There are many version of Linux that can be used on the beagle board XM but Angstrom is the most widely used operating software on beagle board. After installing Angstrom on beagle board XM via a computer, connect the module of the wireless camera directly to the beagle board.
You will have to turn on the wireless registers in the beagle board in Angstrom. If you do not have any previous experience in Linux, you will have problem dealing with Angstrom on beagle board. Place the beagle board along with the wireless camera on your RC car, and use another beagle board to receive the wireless signals and display live video feed from the wireless camera on a television screen.