Carfax is a waste of time, it's not accurate. If you want to get a better idea of the history about a car take it to a mechanic and check it out with him. He will know where to look for damage. Save the $20 and buy the guy an 18 pack.

My crossfire had some front end damage and was owned by Hertz rental cars, none of this information was available to me from Carfax. If it's not reported to the insurance company it won't be discovered by carfax.