http://www.askmid.com/ - Motor Insurance Database check. Gives basic model information as well as insured status.

http://www.webuyanycar.com/ - Gives full model, colour and engine size.

http://www.vehiclelicence.gov.uk/ - Click on 'Vehicle Enquiry'. Requires manufacturer (use another site first) but gives date of first reg, date of tax liability, engine size, CO2 figure, fuel type, colour and tax prices.

https://www.mycarcheck.com/ - Gives basic model info plus full report as above for £3.95.

http://www.motinfo.gov.uk/ - Gives MOT information. Requires vehicle reg and either MOT certificate or V5 reference number.

http://www.warrantywise.co.uk/ - Gives Manufacturer, fuel type, engine size and date of first reg.

http://vpc.autotrader.co.uk/consumervpc/check-vrm-form.action - Gives make, model, transmission, fuel type, body type and colour.

[Edited on 14-10-2009 by Ian]

[Edited on 15-09-2012 by Ian]