Early Mercedes SLs are already classics, so there's no problem there. The early ones -- 300SL, 190SL and 230SL pagoda roof models -- are now bringing quite high prices on the collector-car market, and while the later models aren't yet commanding the same high prices its a fair bet they will become more desirable as times goes on. If you're interested, I would look for a 350SL or even a 450SL. They are quite affordable and will give you lots of pleasurable kilometres. Most Benzes are reliable and will give untroubled service for years. Perhaps the most important thing is to buy a locally delivered car rather than a recent import. Quite a few Benzes have been brought in from Europe, Asia and the US and these can have problems with rust. I would avoid those and look for a car with a verifiable local history.