Potential problem is that with a single inductor setup, if it is an inverting buck boost, then it requires that the plus of the battery be the minus of the output, thus it has an inverting buck boost topology. It is the lowest cost and easiest to make for batter powered applications, the problem with this in a Car PC is that you can't hook anything up to a computer that is powered this way, No wired audio, no LCD that isn't powered off it, etc. You have a high chance of it not working..
here are pics of it, I removed the heat sink, I made some changes
like drilling a hole in the heat sink so the chip could be bolted to
it, all it had was a clip, and was not even making good contact, also
put just a hair of heat sink compound on it,