Valuation of a 2003 Impreza Prodrive STI

[SteveMort]

Hello to all,

How would I go about obtaining a realistic valuation, within the Subaru fraternity, for my son's 2003 Prodrive Impreza STI, Type UK? 

This car has covered 60,100 miles & has all factory issued paperwork, comprehensive service/maintenance records & several upgrades on its 'standard' spec although it remains mechanical as produced. It will be for sale in April although it will need to be sold for its appropriate worth.

Many thanks for any help with this requirement.

Trevor