Possibly worth making a list of useful links to websites and making it a sticky.

Recalls
http://www.vosa.gov.uk/vosa/apps/recalls/default.asp

MOT Status and History check
http://www.direct.gov.uk/en/Motoring/OwningAVehicle/Mot/DG_10020539

Insurance Check
http://www.askmid.com/ownvehicle/

Road Tax Cost Search
http://www.parkers.co.uk/cars/road-tax/

Reviews for New/Used Cars
http://www.parkers.co.uk/cars/reviews/

Used Car Valuation
http://www.parkers.co.uk/cars/prices/

dont parkers charge?

Free Price Valuations
Values for cars from 2000 onwards. Older cars are part of our premium service.

Parkers Plus
Our premium service for valuing cars from 1989-1999.

Its very easy to gauge older pricing using a mixture of Ebay, Pistonheads, Car forums etc to get an idea on anything that falls under 1999 or before.

All the other stuff i linked is free, a very handy website.