Well, as Mike mentioned above, it's clear someone was trying to launder money through you. Very shady to say teh least. Avoid.

But as a counterpoint to all of this, I actually found my DC4 locally via the AutoTrader.com listings. h:
The seller was upfront, the records were complete, the car performed beautifully and checked out fine. Negotiation was swift and easy. No hassles whatsoever.

So... I wouldn't write off the site altogether. Just be wary of the people you do business with.