What do you guys have against roof mount racks? They are much safer up there. You won't bottom out the hitch on anything either. In CO here, we take the bikes into the mountains and in some cases you 4 wheel to your destination to camp or whatnot. A hitch mounted one will get hung up. The H3's roof is low enough that you could put a Yakima or THule mounted bike rack up there if you like that style. And you can still fit in a standard garage height. They both have a rack that uses the factory tracks for the mounting points.
... just another option for you. I did some research and the ones I looked up wil lall get in the way of your rear door. I don't think the swing away will work with the spare tire. I understand it is nicer to load your bikes at ground level, but just is a P I A with the rear door. Here's a couple of links for youto check out.
Good luck,
Tim.
Yakima
Thule