15: 1971 Chevrolet Vega
GM was in a pinch during the ’70s. The Vega was an attempt to combine a performance car with a gas efficient compact. Unfortunately, it ended up a bug-eyed two-door that looked like a mix of a Camaro and a VW Beetle. The Vega could have been a great car had GM put more effort into it. Instead, the car was almost like a Chevy version of the Mustang II, itself a sorry offering.
The hole in the lineup left by the more powerful Camaro was not filled by the Vega. Lackluster build quality and an awkward design made the Vega a sore spot in the automotive industry. There were many duds that came out of GM design at the time and the Vega was one of them.