Copy from a thread I posted on earlier in the year.
"I previously used Brentacre, Manning and Adrian Flux (for the last 3 years). This year I thought my AF renew was a bit high so as I normally do checked around and came up with a much better quote with Classic Line who had been close to my AF quotes over the last few years.
I've also checked with BMWCC A Plan, Hagerty, Saga and Chris Knott over the years. It pays to take a few hours and just shop around as the variations are huge depending on things mentioned in post above. (i.e. Location, driver age, annual mileage, value, garaged overnight, licence points etc)
My last insurance with Classic Line cost £268 with agreed value, garaged overnight and 3k annual mileage limit."
Good luck with your search.