With very few exceptions four door sedans don't become collector cars. These are cars that are going to face economic obsolescence long before the engines and chassis are worn out. It's hard for me to imagine who's going to want to own and operate them as aged used cars - poor people with big egos?, colleges students with trust funds? There's no market niche for them. They are not ever going to be inexpensive to operate - who's going to want to put up with them as daily drivers? Gas mileage is poor, insurance is high, parts and service are ridiculous. To me the historical significance of the 140 body is that it is the first Mercedes not designed for longevity - not because it isn't well built but because it lacks long term economic viability.