"At least the Yugo didn't roll over if you took a corner faster than 5mph."
But they could blow off a bridge. Oh, actually, vanagon man already wrote about that just two posts below. Apparently the car didn't even blow off while moving, it was STOPPED on the bridge when a gust came through the metal grating and blew it over the 3 foot railing.
Anyway, I think Yugo was probably the worst. But I did have a 1989 Dodge Shadow that was pretty bad. Anemic air conditioning (which broke, I repaired and recharged it with R134A, and it broke AGAIN -- Dodge had changed from their "tried and true" indestructable compressor to one that was too weak to handle the ~10% extra load R134A puts on the compressor.) It was dead slow (it was geared to take off up to 50, then run out of any semblance of acceleration, which made merging onto the interstate hair-raising), it got lower gas mileage at 70MPH interstate speed than it did in town (20MPG city, and although it'd get almost 30MPG at highway speed, it plunged to 19MPG at interstate speed). Stuff kept loosening up on it, I was tightening bolts on it at least twice a week so the rattles would not drive me mad. It blew the head gasket (and did for the previous owner as well). Ultimately, it lost compression on one cylinder, and I sold it to somebody who did something to it to block the fuel flow to the dead cylinder, and kept driving it as a 3-cylinder car. The performance versus gas mileage was the worst to me -- I had a 1985 Chevy Celebrity that was bigger, appeared much less aerodynamic, had the same size engine (2.5L 4 cylinder), but got 30MPG at interstate speed and although also slow, would keep accelerating consistently up to about 80 so it was possible to merge onto the interstate with it without loosing hairs.