In fact here is an interesting explanation from one of those results:
"At first I thought this person was going to try and hack my PayPal account but after doing some research I discovered their plan.
The ‘Buyer’ explains that they can’t pick up the car themselves as they work abroad, so they hire a ‘Shipper’ to pick the car up. The ‘Shipper’ charges something in the region of £300, so the ‘Buyer’ transfers the money for the car and the shipping company to your PayPal account – BUT freezes the transaction before you receive the money. The seller (or victim) thinks the money is in their account and pays the ‘Shipper’ the £300 and they take the car away. The ‘Buyer’ then retracts the money from the transaction. So the seller not only looses the car without receiving the sale price but actually has to fork out an extra cost for the fake shipping company.
If you’re suspicious about emails you receive, look out for bad grammar, spelling mistakes or just unusual demands. Copy and paste the email address of the sender into a search engine and see if they come up on any blogs about scams (that’s what I did). Once you’re sure it is a scam, report them to the email provider (Google Mail, Hotmail, Yahoo Mail etc.) and the service through which they got in contact with you, in this case AutoTrader, so that they are aware of the scam."