Don't use a comparison site because:
a) Not everyone advertises there (Direct Line for example)
b) Its more expensive (cos the comparison site wants there cut too...they ain't doin it for love)
(that's true for all products not just insurance)
Do BMW do subsidised insurance for new bikes?
Bennetts and Carole Nash seem to be consistently good value, although Equity Group did me a very competitive deal one year (and tried to screw me the next...as they all do)