1000$ for a NICE 32" LCD (or since it's in a car you could just go for the Olevia, or what ever the hell they are), 600$ for xbox360 plus couple games and controllers ( I would suggest Assassins Creed, and Mass effect... Though only 1 person at a time) ~100$ for power inverter. So thats like 1700$ + mounting equipment, so more like 2000$
I would also put some money into a NICE hometheater "LIKE" system... Don't get 'bumpin' bass... Get some nice mid-high range (as in hz) stuff... I wouldn't play Xbox or watch movies with two 12" woofers... (I've tried it, a nice 8" with really good SQ is wayyyyyyyyyy better)