Recently I asked my machanic to install HID lighting on my FJR1300 which has twin headlights as standard.
Just thought that I would let you know that in some countries in Europe HID lighting is only legal on a bike when:-
1. If you have twin headlights on your bike then one light can be HID and the other must be normal Halogen or yellow light.
2. You must carry spare bulbs with you at all times
3: Your headlights must be on at all times when moving

Most likely you will get away with it until you are stopped by the police or after an accident when your bike is inspected, some countries are worst than others and the penalties differ widely so be warned.

Al