I have been a huge fan of rockymounts bike racks for a long time, both their roof-mounted and their hitch mounted options. I used their tie-rod roof mounted carrier on my car, and have the split-rail carrier for the hitch on the suburban.
Just a heads up: If you regularly park in the garage, or use drive-throughs you might want to have something that reminds you that you have bikes up there.
For example, I used to use one of those clip-on garage door openers rather than the built-in one and whenever I put my bike up on the roof I would take it off the visor and throw it into the glove box. That way I wouldn't just come home, mindlessly push the button and smash my bike against the garage.