So far, I've noticed the Mini Cooper S '65 and the Toyota Corolla Levin (AE86) have these more remarkable widebody options. I think the Honda NSX Type R '92 and the Volkswagen Beetle 1200 are more examples of cars that get more notable changes with a widebody. This is in addition to the Nissan Skyline GT-R R33, the Nissan Skyline GT-R R34, and at least one variant of the BMW 3.0 CSL.
Literally none of these cars you've named have wide-bodies any different than every other car in the game other than the '73 BMW, and the Levin/Trueno.
The Mini counts MAYBE, but absolutely NOT on any of the Skylines, the NSX na1/na2, (which is a damned shame) or the Beetle.