If you require various crumple/impact zones for safety reasons, which are usually all about controlling the impact deceleration over a longer period of time, i.e. less g-force on the occupants etc, then the relevant car parts get larger. Doors get thicker, front and back get extended etc.
I suspect it would be quite difficult to walk back those changes, so it may be better to roll with them a little, and dictate better minimum sizes for car parking spaces. (Which might dovetail quite nicely with the increased weight of electric cars - which apparently causes issues with multi-storey parking structures which are designed around lighter cars, and may not be structurally safe if filled to capacity with vehicles 50-100% heavier than expected).
(Not counting the truly ludicrous outliers - like the mentioned EV Hummer and Rolls Royce etc).