What sort of car & insurance are you getting?
When I got my insurance at 16/17 I had a 1 litre Rover Metro and got third party fire and theft for �700. Norwich Union were the most expensive they quote me about �1200 so it really does pay to shop around. I don't know if these companies that claim to offer cheaper car insurance to young drivers really do, I certainly didn't find they did.
Best thing is to just phone as many people as poss and you'll soon get an idea of whats the best deal.
Also look at confused.com
comparethemarket.com etc.
confused is pretty good as it compares lots of insurance companies rather than if you just phone up one company.