Build one
If you just want to use it at your hangar, they are pretty easy to make. You just need a couple 4' 3/4" angle, (2) 1/2 inch brass pipe caps, a 12" 1x2 wood and a few bolts. You can use a bungie cord if you want to make sure it doesnt slip off.
It wont fold for travel but will work fine at your hangar. The scooter mod is great for flat, but does not have enough power to get it up the slope at my hangar.