One big difference between laptops and carputer is vibration. I used to ride with a laptop mounted on a stand. Went through 2 harddrives before I gave it up. Probably be ok if you put some isolation under it. Another downside to laptops. Not very upgradable, limited ports.
Would it be wise to mount it on top of a layer of foam rubber after I figure out where and how I'm going to mount it? Something to add a little cushion?
Not real sure what I'm getting into on the way I'll mount it but I did see a few of those Plexiglas cases and thought about building one of those , putting a layer of foam rubber on the bottom and a fan or two blowing into the box. Maybe mount one on the side and one on the top. Where ever I need to cool is where I'll place the fans.