In order to get my girlfriend to and from school every day, I drive my car into town, and then use my bike on campus. The back seats of my sedan fold down, and if I remove its front wheel, it's really easy to put my road bike in the car. This is what I've been doing, because it's easier than a trunk rack and doesn't cost me anything.
I have wondered, though, whether this is good for the bike. Most of its weight seems to be resting on one pedal. I can't imagine the pedals - or, even more so, the cranks - are made to resist forces from the side like this. Am I worrying for nothing, or is there some danger to my cranks or pedals? Should I just buy a trunk rack instead?