If you use the DC-DC PSU (such as the Opus) you don't have to wire it to the power jumper on the motherboard, and wire up a power button instead.Originally Posted by Azh2004
I've read enough to know that running a standard power supply with an ITPC isn't as reliable an option. However, in your scenario, the start/shutdown controller wouldn't be needed. Mind you, your PC is either going to stay on when you turn off the car (thus draining the battery) or it's going to shut off with the car. The controller is to allow the PC to do a proper shutdown when the key is turned off.