My worst "used" car was a Ford Escort wagon I bought as a winter beater. Within 3 weeks after it was out of warranty, the cam belt let go. Fortunately it was one of the "new" improved models Ford came out with, so it didn't take out any valves when it suddenly went out of time. The early ones would usually "mangle" the valves when the belt broke, but Fords better idea was to give the valves more clearance instead of fixing the real problem which was a faulty designed water pump.
My worst "new" car was an 84' Corvette, it road like the axles were bolted directly to the frame. The Crossfire injection didn't offer anything that anyone would ever consider "High performance". But the final straw was reading about a Corvette recall in the local news paper on Wednesday, and driving the car just 15 miles on Friday and having the car break down due to the problem the recall notice, (I hadn't yet received) would have addressed.
I got rid of the car in less than 6 mos. so I never experienced the problems the "video game" dash-board supposedly had, or any other of the 1/2 a dozen other problem areas that showed up later on alot of other 84's. I dropped 4K on that deal, and I've been leery of all new Vettes ever since.