How to get cable television in your car and how much it would cost?

I was wondering if anyone knew how to go about getting cable television on a TV I would have installed in my car. Do you contact a particular company? Does the signal fade if you leave a certain area or is it like XM/Sirius Radio where you can get it anywhere? Is the distance in which the cable works limited to a certain area (is this area company specific?) Anyone know from experience or have an idea as to how much said cable would cost? Thank you very much for reading through all of this!