SmartTag2 Magnetic Case

Remix of a cool design by Guy Smets. I didn't have any of the right size magnets on hand, so I made the holes a bit smaller for 10x2 magnets (should be able to fit 10x3 as well, I just liked the extra clearance) and to use a threaded insert instead of a self tapping screw. It worked super well for me and stayed attached to my trailer on a fairly bumpy ride to another town.