[Guests]

This is quite an interesting read and something I've always wondered.

Used car price movements are a classic chicken-and-egg situation. Latest book prices depend heavily on recent auction sales (fed in bulk to Glass's specialists by auction firms), which in turn have been affected by previous book prices. For a moment the whole thing sounds predictable, but every expert insists that the market is capricious in the extreme, and every one of them has a rich selection of stories about surprises.

http://www.autocar.co.uk/car-news/industry/auction-bible-how-glasss-guide-decides-value-your-car

 

[Guests]

At the end of the day its all about supply and demand. If a car is massively popular new, and there isn't that demand there for used cars (like massive luxo barges) then used residual values will suffer and there is nothing guide books can do about it.