how does it work exactly?
what do they do to work out the prices?
what affects what?

for example:

norwich union curently insure a car and, when the renewal comes through it's £417 and change for my father being policy holder and me being the named driver
if i change over so that i'm the policy holder and he's the named driver, the cost goes up to £778 and change
yet
when i put the details into the computer, last month i got a price of £548 and change and yet, the same company (norwich union) is now offering me a price of £438 and change

so what's changed between me telling the lady on the phone at 1pm this afternoon and me putting the details into the computer 3 hours later thats dropped the price by nearly £350?

can ANYONE explain?

not that i'm complaining as i've just paid for it at the lowest price but why all the hard work to get it to a resonable figure?