Acutally just thinking, a "neat new idea" that seemed to pop up in 60s, 70s 80s, Science and Mechanics, Popular Science, Popular Mechanics, Mechanix illustrated et al every 3 years was swappable bodies... The idea being you could have a sporty body, a family sedan body, truck body etc to swap onto the base vehicle frame.
Now oldskool full frames are pretty much out... However, think of a carbon fibre "X" backbone frame with built in battery tunnel, the basis of a lightweight hybrid... and you could have the 2 seat lightweight commuter body, Cd of .15 barely any luggage space, and a family wagon body for weekends.
Amusing thought.... "Inflateable Minivan" you have a low Cd coupe body that converts to a minivan.... bet you could "proof of concept" it on a "dustbuster" van.
I remember The RoadWarrior..To understand who he was, you have to go back to another time..the world was powered by the black fuel & the desert sprouted great cities..Gone now, swept away..two mighty warrior tribes went to war & touched off a blaze which engulfed them all. Without fuel, they were nothing..thundering machines sputtered & stopped..Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice