Bringing a classic European car to Mecum is like bringing Fried Chicken to an elegant dinner party. Their clientele wants to buy AMerican muscle cars, period.
It all depends on your perspective and location. Perhaps fried chicken at an elegant dinner party in Cleveland may be laughed at. The same in the southeast might actually be expected; along with [horrors!] catfish, mac and cheese, and biscuits. It's disingenuous to lay your expectations as a template on everything and everybody as the one and only truth.
I've never bought a car at auction, and never sold one there either. I'd prefer a private sale or purchase in
every case, but that's just me--clearly auctions are big business.
Irregularities in the auction world exist for everyone. Years ago I flew across the country to California to attend an industrial auction; I was interested (as were others) in the electronic equipment from this printing house going out of business. Some guy was there and
bought every piece as we walked around the plant, paying up to 20% more than the average retail for the stuff. Those of us who were there trying to bid on some pieces we needed finally got frustrated and walked out. Something was amiss on that one, there's no reason to pay +20% unless something irregular was going on.
Shill bidding is pretty much illegal and probably much against a contract one signs with any auction. It doesn't mean it doesn't exist, it means it's hard to catch. I've read stories of bidding irregularities at many an auction house, some which garnered some legal action. Anything with legal action is probably quickly settled to avoid undue publicity. Shill bidding is only one kind of auction irregularity, but that combined with all the fees and commissions etc. has me more agreeable to private sales.
In the Mecum Indy 2021 auction currently underway (May 14-) there are 53 MBs consigned. There are a number of Pagodas, at least two 190SL, one 300SL Roadster, 107s and some later (1990s and 2000s) SLs. Many of the newer cars already "sold". I think you have to register or something to get the final hammer prices; those marked as "sold" don't have a price on them. I didn't count them all, but there seems to be over 2,000 "lots" for sale, and that may include boats and motorcycles. Ferraris, Ford GTs, BMW old and new, pre-war classics--you name it, it's in there. Hardly just "American Muscle".