OK just for the record
STOP ASKING IF YOU SHOULD PUT A CARPC IN YOUR CAR,
what do you think people on these forums are going to say.
OF COURSE YES
not too many people will admit to a bad decision or would think that they spent about a grand on a mobile computer and think it is a bad idea for you.
IF YOU GOT THE MONEY DO IT
if you are broke and it will send you to the poor house, dont get started quite yet. Start planning and purchase things one part at a time so you can afford it.
IT WILL COST A LOT OF MONEY
once you get started you will realize that the potential of you computer is much greater than you anticipated and will want to keep adding little features as they become available.
CHEAP PARTS WONT WORK GOOD SO DONT TRY IT
most people will agree that trying to find a way around using a more expensive power supply or trying to use cheap parts will usually end with the thoughts "I wish I would have just bought the better part" read the power supply section on this and any M2ATX thread. Usually filled with dissappointing experiences.
THis is my FYI for the day, dont plan for what you cant afford and dont buy what you wont use.