New to CarPCs? Don't know where to start?
Attention Newbies! A FAQ to the FAQs
FAQ: Will <insert PSU model> Power Supply work with my system?
I would strongly suggest you do a bit of research before going even a step further.
I'm a little shocked that you would go out and purchase a PC for your car and not have this very basic of questions answered yet.
Take your time, it's not going anywhere.