I found my 300D on ebay. Emailed the guy and found he lived about 5 miles from here. Drove over, took a look, tried to get him to come off of the reserve price on ebay ($1500) which he would not do and returned home. After thinking about it for about an hour I called and committed, afterwhich he removed it from ebay. Rode over later that evening and picked it up. I had been looking (on ebay and everywhere else) for a MB diesel (my first) about 8 months.
The 240D was under a shed adjacent to the road on my commute to work.
I sold a 1991 Mazda to a person from Washington, DC off of ebay. Made the exchange in Cumberland, Md (I was living in West Virginia at the time). Sold a 1974 Caddy and a 1997 Toyota from the automobile sales site on Yahoo.
The secret is to take your time.