I managed to sort mine through eSure on a renewal. It went up £30 but still cheaper than everyone else. I pay £60 more for my 1994 Honda Civic (which is annoying as worth 10% of the Porsche).
I can stomach the £30 increase as I moved house twice mid policy, and my new property has no history as the postcode has only existed since September.
Interestingly, I got RAC breakdown cover through my insurer for nearly £90 cheaper too. (full bells and whistles cover for me and the wife in any car etc). At just £120 through eSure, when RAC directly as a renewing customer (for 3+ years) wanted over £200! Madness. Even they didn’t understand it.