This one was mine, a 1998 Mercedes W208. The nice things about it were the cool Mono-Wiper, the engine (supercharged 2,3L M111) and the seats that were perfect for my height. It had a terrible ASR system but came with a LSD, so it was lots of fun in the winter.
The not-so-nice things about it were that the ignition randomly would not recognize the key, a missing catalytic converter, two fist sized rust holes in the front control arms, rust all over the underbody and the absolute worst 6-speed manual transmission I have ever used.
It also had multiple alignments but it didn't take long for the steering-wheel to be off-center again. You could see the tail end "crabbing" in the rear view mirror. There was something very wrong with it, which can probably be attributed to one of the 7 previous owners.
This isn't even counting all minor annoyances like the frameless windows not lowering themselves when you open the doors (that was only a thing after the 1999 model year), the wind noise, the awful interior materials, the broken seat latch in the rear, the trunk lock not working... I could go on for an hour like this.
So anyways, what is the worst car YOU have ever owned?
i owned a very abused 09 civic si sedan.
it was obviously in a front end collision on the driver's side that was covered up by the previous owner. i know this because the headlight mounts on that side were busted and that light pointed way up into the sky. it also darted all over the road because the front wheels were pointed towards eachother. it was so bad that it wore through the rubber down to the metal belts so i had sharp wires sticking out of tires and i cut myself taking the wheels off:(
it had trouble starting because the starter motor was barely holding on by 1/3 bolts and it was for a different model civic. when i got it home i wiggled the starter motor and a bolt fell out.
the clutch master failed while i was on a road trip. i heard a loud ping like a bolt snapped and was bouncing around my engine bay then the clutch pedal went to the floor and i couldn't put it in gear.
everything the previous owner said he fixed on the car failed within a year of me owning the car because he did a lousy job and bought the cheapest no-name parts.
oh and the rear sway bar was fully disconnected and doing nothing.