Alfa Romeo Alfasud
The problem with thw Alfasud wasn't the styling, which was generally praised despite the fact that bizarrely it looked like a hatchback but wasn't. Or the engine which was an enthusiastic four-cylinder boxer which kept the centre of gravity low and helped with the car's keen handling.
No the real problem was that cash strapped Alfa Romeo did a deal to acquire a load of dodgy sheet steel from communist Russia. As it turned out they would have been better off making the cars out of sheets of lasagne as buyers could virtually see the cars rapidly returning to their constituent elements, so rapidly did they rust.