My 510 was like a lot of 1974 cars in that after about seven or eight years the fenders started to rust through. By the time I got rid of it, sometime in 85, all the fenders were like lace curtains, but the damn thing still ran.
Tin worm swiss-cheesed the pocker panels, back quarters and floor in my 92 Sentra. I went over one rugged railway crossing and heard a bump ... then a long scrape. I thought I'd dumped a tailpipe until I took a look to find a goodly chunk of floor dragging on road. That was patched up as best as I could ... and a couple of months later I lost compression on two cylinders. A kid down the road gave me fifty bucks for it, put a head gasket in the engine and it's powering his little truck now. It sounds as good as the day it was minted.