It happens all the time on eBay that buyers and sellers let each other down.
As has been said, if you haven't lost any money most of eBay's procedures for non-receipt of items paid for don't apply. elevant. However, you can leave appropriate feedback to point out that thr seller refused to complete the sale, and you can report the seller here to eBay for refusing to do so: https://www.ebay.co.uk/help/buying/resolving-issues-sellers/report-issue-seller?id=4022&st=12&pos=1&...
eBay will still charge full fees for the sale, so don't be surprised if the seller comes to you begging you to agree to a cancellation. Hold your ground and don't agree to this. If they falsely pretend to eBay that there was a problem with delivery due to your address (which if true would be another reason why eBay wouldn't charge them fees) report this again to eBay, using the link above. Don't forget that by selling the car outside of eBay they have not only denied you the car you bought, they would also be trying to defraud eBay out of the fees they are due or it having been sold here.
Incidentally, If considering buying a motor vehicle through eBay please remember that there is NO BUYER PROTECTION WHATSOEVER for vehicles bought here, however you pay and whether by auction or by classified ad. The result is that eBay motors is a magnet for criminals. In a TV programme about organised crime, a senior police officer reported that one criminal gang alone had registered "multiple hundreds" of fake accounts on eBay to place fraudulent listings for non-existent motor vehicles.
The golden rule to protect yourself is not to pay anything, not even a deposit, until you have seen and inspected the vehicle, checked the paperwork and had an HPI check. Then pay in cash, which is the only method of payment that is safe for both buyer and seller.
If a seller comes up with excuses not to accept these conditions, walk away from it. Good luck!
