I have a Travelrite rack and i'm happy with it. See:
clickySome features:
It comes with a simple anti rattle hitch bolt that works!
Has a center tie down so there is one less bar to whack your shins on.
Relatively light, like 35 lbs.
States only two straps needed, I still use four.
Other stuff:
If you have a center mounted spare, you will probably need a hitch extension.
The standard rack for years is probably the VersaHaul. It's very heavy and you don't need that for a small scooter.
Norm