I'm with Swiftcover. (branch of AXA)
They've doubled up my no claims bonus to cover two cars/policies.
I can pay once to protect both policies NCB's if I want.
No messing around phoning up for quotes and changes, it's all on line.
I can add a temp car for a day, week, month and even tax it or add another driver or temp driver and can swap cars on either policy just by logging in and clicking a few times, no need to wait for a call centre to open (and answer) I can do these 24/7.
I'm also happy with their premiums, no matter who I try they seem to under cut all like for like quotes, even on auto renewal.
They don't seem to increase the premiums just for existing customers on renewal, so the renewal is the same as a new customer quote.
Never had more than a £12 increase in any one of the last 4 years.
They are incredibly cheap for my Abarth, I originally thought they might have confused it with a normal 500!
The Berlingo 1.6 HDi works out a little more, though that's getting chopped in tomorrow, I can't turn left out of my road in it due to the ULEZ as it's a Euro 5 diesel.
All the add ons aren't automatically added on, you have to select them rather than deselect them.
None of that 12 noon mid day exchanging of cars nonsense when it's time to swap cars mid policy, they automatically insure both your old and new car for the whole day on the day you want the policy to change.
Never had to claim yet (touch wood) but it all looks like it's handled on line as well.
One negative is their interest appears quite high if you want to pay monthly, but as I never do it doesn't bother me.
Both cars/policies less than £600 fully comp, considering I live in SE London and both cars are parked on the street I think that's pretty amazing.