We found the Thule Doubletrack XT to be the perfect rack for our SUV. We were in the same situation...we have a Lexus RX330 and after a year of throwing the bikes in the back we were looking for a rear mounted hitch rack. We like the rack in that the tires set in a tire tray and both bikes stay level, not all cockeyed. Then a clamp bar comes down on top of the the frame and can be locked down as well as the pin in the hitch to the car is locked so we feel very secure leaving it. When the bikes are not on, the rack swings up behind the rear SUV door. As far as shopping, the rack does not drop or swing out of the way. But we find no problems loading items through the side door.
We really do like this rack and suggest you look into one. Easy to load, very stable, can be secured.
Check this site:http://www.thule.com/en-US/US/Products/Bike-Carriers/Hitch/990XT-Doubletrack