I use ebay a lot, if you read the fine print I think there's a guarantee on some condition for up to 10 year old cars. In other words, if the guy says there's no rust on the body on a 96 and you discover some rust on a panel, too bad. If the model is a 2000 and less than 10 years old then you have some guarantees. You just have to go through the buyer guarantee.
PS, some people have bought homes over ebay and I've known people who bought homes at auction with only a picture.