[pete-d]

If it does mean sunroof I guess it's to do with what the manufacturer says when they apply for type approval. If they declare separate models with and without sunroof this would be recorded. If a sunroof is standard on all cars of a particular model then it may not be declared/recorded. If a sunroof is a factory fitted option (but not a specifically declared seperate model) then it probably wouldn't be recorded.

Another example that comes to mind is the Peugeot 206 - there was a time that you could get a 206 GL s/r with sunroof or a 206 GL a/c with aircon. These were listed as seperate models even though they were essentially the same car.

Pete