The worst part of this is that insurance companies are so harsh with certain cars. For instance, the Ford Fiesta is really popular as first car and they're are plenty on the market, meaning the prices are fairly low. But. because it's popular and 'more people have accidents in them', they charge way more for insurance, even if it's a Group 3 or Group 4 car.
Worse still is how they sometimes even charge you for different trim levels. The cheapest car I ever managed to find insurance for was a base model Toyota Aygo from 2006, with the quote at about £900. But, if I wanted that very same basic trim level with Air Con, it suddenly rose to £1012. Because why the hell not.
Best advice I can give to you @CadillacDave is a black box, like you say. I'm with Direct Line and they were pretty much the cheapest company I could find for my car, plus they have great customer service.