No bids on ebay are not legally binding in this country, you can bid on a car but you don't have to buy it!
you could bid on a car or anything else, but when you go and collect and theres a knocking sound from the engine or the suspension would you still buy it.....I dont think so! I wouldn't anyway!
I believe a solicitor challenged the legality of these bids in court for some reason and he won, I think the buyer did try and take him to court stating the legally binding bid bit but the court disagreed with the seller!