Jon, just out of interest - when you did your renewal, did you make any amendments to your policy? Because I was just told that any amendments would be an admin fee of the same sort - so I'm just wondering if your extra cost was that? You might want to check if renewal constitutes as a change in your policy (which in respect, it does - since the change is the dates in which it's active...)
To be honest, you don't wanna be grumbling at that cost - insurance is incredibly hard to find for less than 500 quid these days unless you have a near brand new car. (My 2013 Audi A1 180 TSI Turbo Stronic was bought brand new, and I got insured for £340 a year - I'm not sure why it was so cheap, I figured maybe because of the car being brand new, less likely to drive it like a n*bhead, haha, less claims on them in the statistics, etc) - so... I dunno, might be worth asking about that.
In my experience, AF was really good - it took me 10 minutes to get the best quote I've had so far, and get insured. And my level of cover is really high aswell, including key cover optional extra - so I'm pretty impressed. Nay - incredibly impressed! I've been given silly numbers all day like £800-1400... I'm like... mate, I'm 29, I drive limited miles per year, I live in a nice area and don't drive like a tardis, and the last 4 years of my insured life has been with high performance vehicles. Sort me out! Lol. But only Adrian Flux were even able to step up to the table with a realistic sum. I'm a happy camper.