if you can do that, why would anyone pay £18k+ for a car with more miles on? doesn't make sense, for all the obvious reasons.
this may not be want you would like to hear but thats the truth, when i sold the 993, my car was somewhere between £3k to £10k less than an equivalent from a dealer, with some RS6 owners it seems to be the other way.
i understand that people might want close £18k to £19k for a good car with 90k on the clock but unless its exactly the spec that someone would like then i would be very surprised to see it sell for that. while i have been looking i have had several people email me that they would be selling their rs6 and not one of them has appealed with the exception on the one oop north, this shows that there are plenty about to choose from and its a buyers market even though there are not many anyway.
if these cars were less to buy eg £10k then i am sure that this would be different as most people would be happy to put £10k into a car, however they are not, they are £16k+ for a steady one with a cash fund in reserve for repairs; for this reason i think that dealers are more attractive to people like me where i can finance them, so the market is set by these guys. so if you are a private seller and want to sell, you need to be below the equivalent car in a dealer not above it, just as i had to be with the 993.
the fly in the ointment is that people who will be selling their cars on here are by definition, 'enthusiasts' so i would expect their cars to be top drawer and the owners pride and joy. this is where it all falls apart. if we look at pauls car, (i dont know Paul but seems like a nice chap, he has given me some good advice) i would say that its one of the better ones out there, no mods which is what i am after, compare it to the second one...same car less miles but still on the drc, however heres the rub, i am pretty sure that i could get the second car for just over £14k....
http://www.pistonheads.com/sales/1496774.htm
http://www.pistonheads.com/sales/1477062.htm
i hope that no-ones takes this email the wrong way, as no malice is meant.
on one other point re the wardrobe, i dont think that there is another car, with the poss exception of an E class AMG, that can carry a wardrobe at that speed however there are a few that will carry one at 130mph which is fast enough for me, this is why for me £20k + RS6's would mean that i would also be looking at other marques.
after all this i would still love an rs6 avant

best
andy