Well I am not going to say anything about mine as the new VW Golf GTis have LED's and as mine is only 2+ months old, I will simply tell them that VW updated mine as a goodwill gesture!

Fcuk 'em.! 
It doesn't matter whether the extra was a goodwill gesture or not. It is still an extra at the end of the day. But why LED's should add as much to the premium baffles me.
When I originally tried for quotes before receiving my car some companies specifically asked me about the stereo and wheels, if these had been upgraded. Obviously I told them they had. However the company I settled for never asked me about these things until I received a letter from them stating the details I had given them didn't match the details on the insurance company database!!
Big Brother is definitely watching!! I don't know how it would go if you phoned your company to add extras and then went elsewhere.