Of course you won't find well-maintained, high-mileage cars in the used car ads. They're all in our driveways (or garages) for life. People who go back and forth selling cars tend not to take as good care of them. The people who really take care of cars are the guys who intend to drive it untill it just isn't practical to keep on the road anymore or untill it just rusts to oblivion.

Oh, and everyone ragging on Caddy should take a look at a real Caddy. I've got a 1970 Sedan DeVille with a genuine Caddy big block under the hood. The car has no more general issues than a MB of similar vintage.
I have to say though that the quality of the MB door seals on my 1971 220D and just the general feel of the controlls overall is more solid than the Caddy.