2002 Subaru Impreza 2.5RS... purchased new.
On the day I purchased it, I put it up on my hoist and gave it a once over. Imagine my surprise when I found the bottom of the transmission coated in gear oil (manual transmision). I cleaned it off and went on my way. 1,000 miles later, at the first oil change, trans coated in gear oil again.
Turns out the transmission case was cracked. Repair under warranty. Somewhere along the line, a leaking shock was also repair under warranty.
After the warranty:
Clutch pedal would stick to the floor when hot. Replaced slave cylinder.
Evaporator would ice up on really humid days. There was a bulletin on this one specifying replacement of the TXV. Never repaired due to complexity (instrument panel removal).
The following one is what did it for me. The one issue that solidified it as the worst vehicle I ever owned: Rear wheel bearings.
See, in 2002 the Impreza utilized a cartridge-style bearing with a pair of ball bearings. That's right, ball bearings, just like a 1950's Chevrolet. In 2002, the Legacy used tapered roller bearings, which the Impreza also received in 2003. You see where this is going...
Subaru used ball bearings in the Impreza as a cost savings. The Legacy used tapered roller bearings, which were 100% interchangeable with the Impreza bearing, because it's a larger car. When Impreza bearings began failing, Subaru instructed in a TSB to replace the bearings with the Legacy's tapered roller bearing and made the change themselves for 2003 in the Impreza.
Subaru being cheap means I needed to replace rear wheel bearings at 65,000 miles. On top of that... they're fricking cartridge bearings! Disassemble rear suspension to remove knuckle, press out hub, press out outer bearing, press out inner bearing, press in inner bearing, press in outer bearing, press in hub, [censored]! forgot to get seals, order seals and wait for them to show up, tap in seals, reassemble rear suspension. I'm sure if Subaru was too cheap to install a proper tapered bearing, there was no way they're were going to installed a unit bearing.
I ended up selling the car to a co-worker's kid at about 100,000 miles. He drove it for another 20,000 miles before trading it in...
...because the head gaskets were leaking.
Of course they were!
Only in a Subaru.