well, people keep thinking about heat, right? ok, most of the time, the extremes of heat for your car, are when you're car is sitting there doing nothing and has been and the windows are rolled up and the doors are locked. Chances are, if your car is that hot, it's because you're not in there. right? and if you're not in there you're Probably not using it. I say probably, because I know myself and other people around here.
So it's Fairly safe to say that if you're just running it while you're IN the car, you should be good. because a processor can RUN well into the 70's celcius, if it's a recent pentium it'll just start underclocking itself and slowing down. besides, if you're sitting there and the ambient is 70, you're probably well on your way to dying and you're probably allreayd passed out.
Undervolt and underclock your processor. keep it cooler. and for when you're not in your car, don't run it. if it's the dead of winter, heck you've got an extra space heater for your car if you don't allready have heating.
if you want to do watercooling, add another raidiator to you car. Our van has a small rad for the transmission. bolted onto the front.
yes, IHS, good idea.
integrated sound will probably be plenty good enough especially on an nforce2 board
go for it. and if you can find good prices on those LCD's let me know, I want one for my suitcase