Mercedes has a TV-tuner with 2 auxiliary A/V's that you can purchase and enables the cars' Comand system (which includes navigation) to receive TV broadcast or show what is fed to either of the two A/Vs.

The system shuts off the screen when the car is in movement, but there are hacks that enable you to disable that feature so you can watch while you drive, which is absurd in the case of DVD, but not so when you just want to see what your Empeg is playing and control it.