Always take a good look underneath.
If it has been forklifted, most likely damage will be bent driveshaft, a bent/crushed transmission pan, fuel tank, and running boards. Some transmissions may receive much more damage than just the pan.
If a fork was placed under the fuel tank, where the pick-up/sending unit is located, that too will probably be mangled.
And goooood luck finding replacement parts. Most of the salvage yards around here also forklift their cars.
Literally thousands of ruined driveshafts, fuel tanks, and transmissions, that were good takeoff parts before the forklift. I've spoke to several managers, but they don't care. One yard drills 3/4" holes in the fuel tanks to recover the gasoline, and ruins the tanks the forklifts miss. Pretty darn frustrating to find dozens of needed parts, but all ruined by a forklift.