Insurance is all about risk assessment and previous payouts. Over the years, I found these make the most difference:-
Negative
If you're < 25yrs old
Have little NCD
You have numerous convictions e.g. more than 3 points
Your job type (e.g sales)
Your average milage is high
Insurance companies previous payout history on certain cars
High Insurance group (speaks for itself)
Bad Post Code
Positive
Good/protected NCD
25+ (30 even better)
max 3 points on license
you work in an admin-type job
low social/commuting milage
the car doesn't have a bad history e.g Subaru Impreza - some companies won't touch them now.
Nice, safe (boring) post code
Best advice is to shop around. Elephant, Bell, Admiral were all pretty reasonable when I was insuring my Impreza.
Also try adding your mum/father to the policy as that's knock hundreds of pounds off mine in the past. Even better if you can insure through the same company as your parents own car or home insurance.
My 9yr old Impreza valued at £4K is £200 more to insure than a brand ew
CTR worth £20K !
Stefan