Flipping heck, you have 1 accident in 28 years and my insurance has more than doubled, i have tried AF/Direct Line/Quinns as well as the comparison sites all coming back between £900 up as far as £1400.
I wouldnt try Quinns if I were you. Their UK arm went into receivership in the week!
My own insurance is with Admiral.
Speaking as someone who works in the industry, you need to be a bit more savvy. Pick a price that you think is reasonable, then call Admiral for a quote. If you can, get a genuine quote from somewhere first. If their price is no good then tell them you have had a quote for £xxx elsewhere (make sure you have a company name, your call is recorded!). See if they will bring their price down to match your "quote" and hey presto! Job done!
Or try your local high street broker. Everyone forgets using them but they may have a special scheme with an insurer that can better the direct writers or those who advertise via the price comparison web sites.
Despite the insurance market "hardening" in the last year or so (i.e. prices going up!), insurers still want your business, so just haggle a bit and you should get a good deal.
I sell car insurance for a living, working for a broker, so I know how to play the game. PM me if you have any further questions!
Cheers guys. Andy