I sold the Audi recently. Yes it's a bit of a chew dealing with punters but I worked out an hourly rate for the time I spent as follows:
(x - y - z)/t where
x = what I got for it
y = what the cunts at "WE RIPOFF ANYONE.COM offered me
z = cost of running advert on Auto Trader
t = hours spent preparing advert and dealing with buyers, dickhead canvassers etc.
It came out as £1270 per hour.