Hmmm. First thing I noticed about this auction (other than the very nice 1982 Mercedes) was the information: "Ends Jul-14-03 19:00:00". How much time did you allow for your snipe? If it was less than 15 seconds you probably have your reason why it didn't go in: auctions that end on the even hour, half-hour, or quarter-hour are like rush hour in Manhattan...bids coming in from all over the place. By way of explanation, eBay offers a "special" which allows sellers to select their own beginning -- and therefore ending -- times. So many sellers choose an even hour, half-hour, or quarter-hour that eBay's servers get overwhelmed by the bids coming in during the last five minutes or so on these auctions. If you don't allow at least 15 seconds (more if the auction's on a Sunday) you run a serious risk of your bid not reaching eBay's servers before the auction, on which the clock keeps ticking regardless of incoming bids, closes.
I'm not saying that this is definitely the reason for which your snipe didn't get placed because I can't be certain. But it's surely one good reason why not. Sorry...but there'll be another 1982 Mercedes sometime. Things always come around again eventually.
