The "fat bingo caller" still owns the place, he does the odd auction but its his son who does most of them now.
The "ghost" bids are usually to try and get a car up to somewhere near the reserve.
For example, a car goes in with a reserve of £2000, there is a bid of £1000, which he knows the seller wouldn't accept, so he ghost bids (or takes bids "off the wall") for the car up to around £1700, still below the reserve, but if a real bidder (maybe the only person who wants it) now comes in with a bid of £1800 he can put that to them and it might be accepted.
This usually only happens with vehicles that have a reserve, no reserve, VERY low bids and cheap cars get people talking and coming back.
The auction will usually start with a cheap one, something with no reserve to get people bidding, and it'll sell for next to nothing and after a few slow bids it'll go fairly quickly as well. Now it's implanted in your head that it was a cheap car and that "one more bid" and it could have been yours, now you'll bid higher on the next ones (today's free psychology lesson).
The trade-ins go through later on, and they're usually the straight ones, but think about why it's there. Sometimes it's because the company doesn't have the room to keep them, so they'll put it through the auctions with a high reserve, so it usually doesn't sell, and it's free storage (main dealers don't pay each time a car goes through as everyone else does, it how the auctions entice them to let them sell their cars, if they don't have any to sell, no one will come), sometimes it's because it's not their "thing" (M53 Ford selling s/h Vauxhalls or a oldie they took as a p/x).
The ones to be aware of are the private entries. Some are legit, and you can get the odd bargain, but you have to wonder why people would pay to offer their car for Sale
, at a place where they would get the least for it, of which they have to pay a percentage, and you don't get your money for a week or so.
Best advice I would offer you, talk to the drivers, the ones taking the cars through. They are on a sh!te wage for doing it, they get treated like cr@p half the time, but in general they're a good bunch and will tell you if they know anything.