There are only OLD "muscle cars, but ONLY NEW Performance Cars"
No "New Muscle Cars".
But there ARE "Old Performance Cars".
"Muscle Car": Those marketed and/or sold to race orientated buyers, OR the younger/not so wealthy car enthusiast of the era.
"Performance Car"; By today's marketing scheme; jamb as much performance equipment AND also the "luxury" items into it & sell for high $$$. Thus maximizing profit.