Some DVD tuners play CD-R,MP3,DVD,DVD-R,and CDs but most of these are mounted underneath one of the seats. Making it very dificult to load and unload Cds.
These can also have TV tuners that pick up local stations (unless you strap a Direct TV Dish on to your ride) but usually come with ugly TV antennas that you have to mount inside your car. Some also have auxiliary inputs for things like playstation, gamebox, and videocassette players.
It all depends what your looking for...