A: It’s possible, but unless you’re an especially avid DIYer, you’ll probably want to get professional help to avoid damaging your car’s interior.
The job is really pretty simple–you just need to run a video cable between the DVD player and the monitors. To do this, you’ll need to make sure that the DVD drive’s video outputs take the same type of cable as the video inputs on your monitors. The outputs are on the back side of most players, so pull the DVD drive out of your car’s console and inspect. If the outputs don’t match up to the screen’s inputs, you’ll need to purchase an adaptor.
Connecting the two isn’t difficult, but if you want to avoid filling your car’s interior with messy wires, it’s probably a good idea to run the cables through your console and under your car’s rug. If the rear monitors are nested in the back of the front seats, you’ll also want to run the cables through the seats. This can be tricky, so using a professional installer may save your seats.
One thing to keep in mind: If your system only has one DVD slot (as opposed to a changer), you may have to repeatedly swap map and movie discs.
Even if your unit doesn’t have a DVD drive, it may still be able to play movies. Many GPS systems that use memory cards to store map data are also capable of MP3 and digital movie playback.