I am selling a car on Ebay, its only worth a few hundred quid.

There are a few bids and the auction ends tomorrow. All was going well but the highest bidder has zero feedback. I am a bit worried about this as been told stories of people messing about on Ebay when it comes to selling a car. Shall I message the highest bidder and ask if he is 100% interested or just leave it till the auction ends?