KF 8040, Liquid Tight Polystyrene Enclosures (Indoor/Outdoor Installations): Smooth Wall (No Knock-Outs)
Here is the box I used. We use quite a few of these at work so I just used one, the system says we paid about $5 so thats my cost. I had to trim the lip off the top so it would fit where I wanted in my dash. I also had to carve out some spots on the inside with a dremel, and of course make the openings. The boards are held in by screws and rubber hose on each side of the screw, hopefully will give some stress isolation.
Its the same components in post 484, with the reset button added. But if I did it again, Id put it on the side away from the other buttons, still might do that. I also might add a switch to go between USB power and car power. And maybe a switch to turn the display on and off, rather than running another wire for a relay or transistor.