I've been getting quotes for insurance for a few months now and have found that if you add someone who has had their licence alot longer, it definitely brings the premiums down. with regards to the relation of bike and car insurance policies, i think the insurance companies just like to relate the 2 in a way that will benefit them. i.e. if you declare that you have 1 years no claims on a bike when trying to get a car policy, it means nothing, whereas if you declare that you had an accident within the last 5 years on a bike, they will happily penalise you for it by bringing your car policy premiums up regardless of fault. I know this probably isn't the sort of information you were looking for but your question just reminded me of it and I had to rant! :-)