Unfortunately the site isn't much use, as dealers register the cars under all sorts of different guises (even for the same model).
For example, a 2.5 V6 75 Connoisseur SE automatic could be registered as:
- Rover 75 V6
- Rover 75 V6 Automatic
- Rover 75 Connoisseur V6
- Rover 75 Connoisseur SE V6
- Rover 75 Automatic V6
etc etc. You can see how many different combinations there could be!