No hitch here, so I usually use my Saris Bones. It'll adapt to anything, and I mean anything.

I also have available a roof mounted Thule 2 bike rack. I've run long trips with and without bikes on the roof - presence of bikes seems to make little difference with respect to gas mileage. BUT NOT SO of the rack itself. Even an empty rack knocks my mileage down by 10%+ on the highway (2015 Passat 1.8L turbo).