There really is no limit to the size of the screen of your car’s DVD player. As long as it will not obstruct your view of either the front or rear of the car or that it will not detract from the overall aesthetics of your car, you can go as large as you want. Vans and SUVs can really benefit from a large 13-inch screen, although the same may not be said of a small compact sedan. In-dash systems will also be limited by the amount of space available on the console. The largest car DVD player available in the market today is a 14-inches from Pyle.