Why is this? Just a time restraint thing, or what? I don't understand why an auction wouldn't allow bidders an opportunity to check out the product before they purchase. The pessimist in me would say it's in the auctioneers best interest to give as little information as possible, in order to get the highest bids, but it seems odd that this sounds to be a standard practice.
Shouldn't bidders insist on at least a single 3rd party to say the mileage for the crowd?
I agree though that changing the odometer is criminal to do. But one shouldn't be buying cars at auction unless they know what they're doing. Buying a used FedEx van at auction comes with a few known... stipulations.