6. Chevrolet Corvair

Few cars have sparked as much controversy as the Chevrolet Corvair. Its rear-engine layout and unique suspension design made it notorious for unpredictable handling, especially in emergency maneuvers.
Ralph Nader’s groundbreaking book, Unsafe at Any Speed, brought national attention to the Corvair’s instability and rollover risks, casting a harsh light on its street legality.
The debate surrounding the Corvair ultimately helped reshape automotive safety standards—but it remains a prime example of a car that probably shouldn’t have been allowed on public roads.
Source