Sometimes those carfax things don't show everything either. A car dealer buddy just brought back this shitty RAV4 that had $2700 in damage on the carfax, but when you look at the vehicle you can clearly see the roof has been painted in addition to some back quarter panel damage and stuff on the side.
My guess is a rollover, but he swears up and down someone must have just jumped up on the hood and ran across the roof.
Shady fucking bastard.
If someone smashes something up and doesn't run it through insurance, then it's not going to be on a carfax. Happens all the time with drunks that don't report their accidents or people that already have insane insurance rates.