Don't forget that there are insurance brokers out there and, under certain circumstances, they can get good deals.
A few months ago the Doris treated me to a mid-life crisis car. I'd got a few quotes in my pocket from online insurers (a few wouldn't insure directly, but passed through to specialist insurers) but asked the dealer for advice. He put me on to a broker who found a quote £100 less than the cheapest online, and that included 2 days worth of track insurance

and a few other nice-to-haves.
If you accept that the middleman needs to make his money, they can provide qood value.