As in, easy to pull out and plug in new pieces, , like a new dashboard, or the instruments within it, new steering wheel, seats, window controls, engine, body parts, you name it. With a uniform interface across all cars. Radios are the closest, but even those often require pulling the thing apart and they don't have a universal interface. I'd like: flip an unlock release latch, pull out, push in, lock.
Think how much innovation there'd be. All sorts of companies could make components. Do it yourself components too.
(And the chances of that happening are..... Hey, one can wish, right?)
