Not really car electronics but...
If so, I would buy a 120v AC to 12v DC transformer from Radioshack for power, then using a cable box to convert the coax cable input, then the RCA (yellow) video output of it to feed the screen. I believe that should work.
If so, I would buy a 120v AC to 12v DC transformer from Radioshack for power, then using a cable box to convert the coax cable input, then the RCA (yellow) video output of it to feed the screen. I believe that should work.

