17: Chevrolet Monte Carlo Z34
The Monte Carlo from the 1990s was a sore spot for the storied automotive line. The car went from being a rear-wheel drive V8-powered car to what was basically a two-door Lumina. The V6 was lampooned for being underpowered and having cheap build quality. Early on, dials would fall off of the dashboard, plastic pieces would break, and there also was a defect with the air intake manifold. Consumers were upset that a car with such questionable build quality had the Monte Carlo name on it (via Repair Pal).
The Z34 was the furthest thing from exciting to drive that GM had released. The stock rims were not exciting and the lackluster paint scheme only added to the cheapness. Had the Monte Carlo gotten an original treatment like the 454 SS and the Impala SS it would have been a notable success. Unfortunately, GM dropped the ball on this generation of the Monte Carlo model and the brand never seemed to recover from the blunder.