Thanks for the link, but it looks like the results don't account for extras or specific mileage.

I checked on Glass's website and paid for the full report with extras and low mileage adjustment and the suggested value was about £19K for trade in.

SEAT dealer offered me £15k
 
was thinking the same thing.

i suppose if you put the dealer hat on, would you order a car in on the basis that you dont have any security or deposit to fund it ?

still an arse for you though mate