What’s the worst amount of body damage/bondo you discovered after you bought the car??

I owned a car with a lot bondo but I had a Plymouth Trailduster that I redid some years back. I sandblasted the roof and it was rusted through above the drip rail across the windshield and above the front doors. I ended up spraying the inside of roof with spray foam insulation to fill in the gap and then adding a skim coat of fiberglass to finish it up. I then painted the roof with a textured paint and it looked great.