I think that that is a generalisation, choice and availability is better "down south" - so that will drive prices down, even although the bulk of the population is "down south". There will always be HOT spots and COLD spots, up here in central Scotland, Edinburgh prices are very high and Glasgow prices are lower - due to Glasgow people being "looser" with their money (tight wads in Edinburgh), Newcastle is also roughly same as Glasgow. Aberdeen, with oil money will always be dearer, though it really depends what models/marques and which sector of the car market you are meaning. Put it this way, when I was looking for a secondhand B8 S4, it was well down south that most were located, though maybe in just 3 or 4 areas. Anything near Birmingham and outside the Audi network was cheapish or down right cheap and so very suspect Pennine Motor House especially - I think "BEWARE" is the term I'd use there!