Tony, as long as you know the number plate and make of vehicle you can search the DVLA database, but this will only show if the car is currently taxed or SORNed, or the date it was last due.
EXAMPLE: My Z31
Date of Liability 01 09 2008 (This shows expiry date of current status - See below)
Date of First Registration 24 10 1986
Year of Manufacture 1986
Cylinder Capacity (cc) 2960CC
CO2 Emissions Not Available
Fuel Type Petrol
Export Marker Not Applicable
Vehicle Status SORN Not Due (If taxed this says "Licence not due" - If not taxed or SORNed will say UNLICENSED )
Vehicle Colour WHITE
Hope this helps