What is a muscle car

Definitions

MUSCLE CAR: any of a group of American-made 2-door sports coupes with powerful engines designed for high-performance driving.
"The Muscle Car is Charles Atlas kicking sand in the face of the 98 horsepower weakling"

HOT ROD: noun Slang. an automobile specially built, customized, or altered for fast acceleration, power, and increased speed.

This list was how Wikipedia broke it down (not that I agree- Challenger a pony car???) with varied examples: