You are NOT covered by eBay/PayPal protection plan when purchasing a car, or paying a deposit, regardless of whether you win the car on eBay or not.
PayPal Terms of Service13. PayPal Buyer Protection
13.4 Conditions for reimbursement
You may be reimbursed under PayPal Buyer Protection for a problem with a purchase only if all of the following requirements are met:
A) Your purchase is an eligible purchase. Purchases of most goods and services are eligible, except for purchases of the following :
i) real estate (including, without limitation, residential property);
ii) businesses (including, without limitation, any items or services forming part of a business or corporate acquisition);
iii) vehicles (including, without limitation, motor vehicles, motorcycles, caravans, aircraft and boats);iv) custom made items (unless they are claimed to be Not Received);
v) goods and services prohibited by the PayPal Acceptable Use Policy;
vi) items that violate eBay’s Prohibited or Restricted Items Policy;
vii) industrial machinery used in manufacturing;
viii) items equivalent to cash (including, without limitation, gift cards);
ix) goods and services purchased using Zong, Website Payments Pro, Virtual Terminal or Personal Transaction payments;
x) anything on eBay for which the listing does not contain a PayPal Buyer Protection message or an eBay Buyer Protection message (you can view this message in the listing after you complete your purchase by logging into your eBay account, going to “my eBay,” then “won”, and looking at the listing);
xi) any wager (whether by way of backing or laying against any outcome or otherwise) and any other opportunity to benefit from a gambling activity (if you are purchasing as a UK resident user of PayPal);