Back in the early days of motoring, luxury automakers would sell chassis to their wealthiest customers who would them commission coachbuilders to put on a bespoke body. This process doesn't really work on modern cars these days, because the body and the chassis are forced to be structurally integral for crash and pedestrian safety reasons.
And re-engineering the exterior of a vehicle for the sake of one customer while being able to comply with regulations would likely cost millions of dollars, if not closer to a billion. However, there are a few rare examples where the art has been kept alive. Touring Superleggera is a world-famous Italian coachbuilder, most well-known for creating the 8C-based Alfa Romeo Disco Volante.
