I'm a total noob but I really quite like my Hollywood rack, cost only about 100 bucks:

http://hollywoodracks.com/trunk-rack...trunk-rack.htm

Never owned another one before, so take that into account!

Regarding someone ripping off a bike rack, I've only been using this for a few weeks, but just the other day I came back to my car and the alarm had been triggered (in a pretty busy parking area too no less)--I have to assume someone was messing with the rack and couldn't get it off quickly. Now I stow it in the trunk for sure. Collapses very easily.