I can't see Gray's bothering sellng off all the parts independantly like that. I'd think they might do motors and stuff, but for an auctioneer, I'd see them entertaining someone buying EVERYTHING, but they aren't going to auction off every headlight, tailight, hood, etc......that would take days.
Having been to a few dealership auctions, usually the smaller stuff gets put into lots. You want a headlight in the pile? Well, you also get to take home such things as courtesy car vinyl stickers, bathroom paper towels and a box full of blank keys. (Yeah, they can be that random at times.)
There's another thing they do that DeLorean can probably explain better where individual items (I've seen them do this with those suitcases of specialty tools the manufacturers send out to dealerships) get grouped up as you go along to speed things up. So, instead of selling off the suitcases individually, the auctioneer will say, "OK, how much with you give me for the ones you want?" Or something along those lines.
Also, these are car dealership/repair shop auctions. It's not like what you see on TV with last-minute agonizing phone bids coming in from some billionaire on a yacht off of Hawaii buying up rare art.
The one thing I would check into if I could go to that auction is to make sure it is absolute. That means the last offered price means the item is officially sold. Sometimes auctions will run where the last offered price has to be approved by the folks who own the stuff, usually at the end of everything. That sounds like a lot of hassle.