I don’t know the answer to this one but comparing buying price to AP does make it look like something is going on. Could be just the manufacturer wanting to shift a particular model or clear the shelves but tracking the AP prices of the very few cars I find suitable for me the VW Touran has been very stable for near on two years now whereas the Seat Tarracco has gone from reasonable to beyond believe.
I think some of the AP prices show the depreciation of the car after three years and that can vary by fashion or government policies i.e. introduction of extra taxes or charges for diesel cars as an example.
End of the day it’s we disabled folk who have to pay for misguided government ministers.
Thats my two pence worth. LoL