Don't get me started on car insurance...!!!!
1st rule is NEVER accept the renewal quote - always get new quotes - do all the comparison sites THEN get quotes from the Company's own website. Elephant/Admiral/Bell will ALWAYS send you an inflated renewal quote and its as simple as getting a new quote on their website (mispell your name & postcode but other details same) if lower ring them up and they will match it.
mispelling the name is fine, postcode however not so much as it is something they rate upon
2nd rule is 'tweak' your quote details but DO NOT LIE - tweak your occupation, if you have a driveway/garage use it, if you have an alarm/immobiliser fitted check if its thatcham 1/2 approved and enter it, under estimate your cars value, try a TPFT policy, work out your annual mileage and enter it spot on - another thing which saved me £150-200 in years gone by is adding older/female additional drivers - sounds crazy to add 2 additional drivers to your insurance but with companies which use 'set formulas' it resulted in a healthy discount - don't add anyone who has had acciddents/claims/convictions in last 5 years.
# additional drivers is an easy one to work out why its cheaper, if your a 17 year old, sole user of the car their system works out that 100% of the time the 17 year old is driving it, add on mum or dad and their system will take in to consideration that they MIGHT not be the only one using the car, hence the lower risk. the mileage one is a given as less mileage your doing , the less your on the road, less the risk of claiming.
3rd rule is cashback sites - check quidco & topcashback for insurers offering large cashback and check their quotes. Chances are they are overpriced to start with but you might just get lucky.
this one is true
Last thing to try is insuring the car with the wife or other relative and adding yourself as an additional driver. You won't get NCD but if it brings down your premium it might be worth it.
similar to point two, if you got access to other cars more chance that you will be using other cars not just the one your a policy holder of
Good Luck.