Whilst the CAP clean figure can seem quite appealing to the novice auction buyer, even if you have a trade account at BCA (silver or gold and above), the indemnity fees on top of the hammer price on low cost vehicles can seem relatively high. For private buyers (blue), the indemnity fee is particularly high relative to the hammer price. Top spec good examples do tend to get good prices at BCA, as they are a relatively rare sight now in the 'block', and the traders that do buy them know that they can sell top spec good examples quite easily. Internet bidding has had a tendency to push prices up a little; traders who otherwise wouldn't have bothered to travel for a 'budget' cost vehicle, can now bid from their office chair, and if the car they buy ends up being a 'dog', the loss of a few hundred quid if they are buying numerous vehicle in that particular auction is no dramatic loss. Whereas there used to be comprehensive condition reports on vehicles which had to reasonably reflect the actual cars condition, vehicles of an Omegas age now only have photos for you assess the condition on line, not a more detailed condition report, so as with any photo, you takes your chance. Internet bidding is only available to trade buyers however.
As with any auction, it is always recommended looking at the car in the flesh beforehand, but unlike EBay whereby if the car isn't as described when you see it after the auction ends, in theory you can walk away; once the hammer falls at a car auction, it's yours!
If you are fortunate enough to find and buy an Omega in a Police Vehicle auction at BCA (which will be like hens teeth now), this is where the true bargains overall cost wise can be found - the indemnity is only 5% of the hammer price. For example, last year at BCA, I bought a 2003 2.6 Elite auto in 'go faster' black, 98k, owned by a Leasing Company but used by the Police since new, a few very minor car park dings (which the dent man got out quite easily), an 11 stamp Vauxhall service history plus maintenance printout including recent cam belt etc, 4 nearly new Michelin Pilot Sport tyres and overall a very tidy well looked after car, and the indemnity fee was only a smidge off £30, whereas in a normal auction the same figure would have been around £150 to a trade buyer (depending on the account held). Slightly over book price (you can work that out for yourself!) which I didn't mind because of the car itself and the low indemnity, but a superb car.
Always take someone with you who has auction experience if you go with the intention of possibly buying a car.
Just an insight for anyone thinking of going to BCA following on from joshwyatt's info. I have been buying cars there for over 30 years - maybe 'teaching your granny to suck eggs' for some OOF members, but to others, it may be of some help.....