we have a lexus Rx330, and have 2 LCd screens in the back, on a recent trip to sydney i tryed to plug it in to the car, we have a 600w inverter, which we connected to a cigarete lighter. the xbox will run for about 2 seconds, the whole time the inverter is having a hissy fit, beeping. then it cuts out, i run it with the engine on, and it goes, but still beeps when i try to load a game, infact anythime it has to think it beeps. so, i cannot imageine an xbox pulling anymore than 100w, so, what i am thinking is that there is a limiter on the cars interior power-outlets, of 175w will this impede the inverter?, am i looking in the right direction and start ti find how to remedie it? any of you electrical guys gimme a hand? thanks.

weather it matters much, i have an 1.1 v xbox, smartxx v2 and a 200gb hdd.
anyway, thanks.