We are planning to buy new bikes (first bikes in decades) and already looked into adding a hitch to our car (4-door sedan) to hold a rack. The thing that scares me about the rack is that it (and the bikes) then become the fender. If someone hits us from behind, no matter how soft, there go our bikes.
Last time someone ran into the back of my car was the late 70s, so it's not like it happens every day..... I'm just afraid that with bikes on the back, we may as well be saying "Hit me here". And people follow so close anyway. Maybe a roof rack would be better?
What are the pros and cons of each?