I agree with Tjin. Roof racks are fine for ski's, but for any serious packing it should be inside. I'm reminded of the insurance commercial when some guy drives into his garage with two bikes upright on the roof of his car

I like the idea of a trailer hitch bike-rack though. As it is if things go south due to a fire I will lose my bike, now hanging from the garage rafters. A bike rack would allow me to take it along and give me a transpo option when gas could be tight.