I would’ve thought any new crash regulation would guide car form to be ‘bigger’ and ‘blockier’- bumpers and body panels need space to absorb shock.
Muscle cars are meant to look big- big heavy steering (hence you need muscles to drive them- ‘muscle car’), performance from “no replacement for displacment” type thinking, rather than from subtler improvments.
I like how high off the ground muscle cars are, and the big open mouth grills- but if technology doesn’t require this (i.e. most air flow to cool comes from underneath, a modern V6 is better than an older V8) doesn’t a muscle car become a marketing definition more than anything else?