I had to think about this for a while, because their are POS cars that you never expected better from and their are cars you planned to depend on that turned out to be POS.
I've bought a lot of old Porsches for parts or to fix up and flip. Some I drove for a while, some were beyond driving. Probably the biggest POS porsche I ever bought was this '65 SC coupe:
I bought it because I didn't see any damage to the engine. (Should have gotten a PPI
) The only thing on that car that wasn't bent, broken, or cracked was the gas cap door.
The biggest POS driver was a '65 Volkswagen that my girlfriend gave me so I could take care of it for her.
(At that age it seemed like a good trade - pu**y on tap and all I had to do was keep this car running). God that thing was a rusted and worn out POS. The last straw was the evening we went out for ice cream and her son gave some ice cream to the dog riding with us. The dog puked in the car, which made the kid puke in the car, which made me want to puke. We were half a mile from home and I parked it by the side of the road and we walked home. The car was such a POS it wasn't worth hosing out. I went back later to get the plates and I never saw that awful car again. It wasn't long before the girlfriend was history too.