I have been keeping a close eye on the 156 GTA prices as I will hopefully soon be in the market for one (buyer for my Japense box turned out to be a timewaster so have to readvertise

).
Over the last couple of months the prices have dropped like a stone, especially for the 2002 models. The one linked at the top that didn't meet the reserve of £7.3, had been on Autotrader at £9k just a month or so back

(just a shame I haven't sold mine yet)
I doubt the new VED will be that widely known, but when it kicks in and with fuel hitting £5 a gallon (in old money) then I would guess we will see good cars hitting the sub £6k mark sooner rather than later.