There are many different angles that have been worked in these scams.
One angle is the check itself. From what I understand, it goes something like this. What they do is give you an official looking document from an overseas bank that you deposit and your bank then processes for their payment. Because of your bank's policy that states they won't hold funds for more than example, five days, they credit the amount to your account, which you use to indicate it cleared (sounds logical), but then several weeks later, when the check proves to be bad, the bank withdraws the funds from your account. The car is gone and so is your money. You are still responsible for the funds because yours was the last signature on the check. You'll receive the check back to persue collection from the previous signer, probably the issuer, but you'll not be able to find him and you'll be screwed. As in all check deals, the last signatory is responsible for the funds, working its way back to the originator. If there were five signers, it works its way back until somebody can't collect from the previous, and he becomes the one who got screwed. If you somehow proceed, discuss this concern with your bank and don't release the car until the bank tells you they have been satisfied completely.
The other is when they come up with schemes, however convoluted, that result in them having your bank account number and/or your signature. They may start the process some other way that appears legitimate, but then call you with the, ".... oh yeah we forgot or, the bank said... or, but we need your acct. number for X,Y,Z reason".
Are those cars that hard to find, that desirable, or that much cheaper over here that the deal sounds like it has any legitimacy?