Vindis St Ives have a Cali specialist - unusual as they don't have a demonstrator Cali or a sales team who seemed very interested in selling us one (we bought our Cali at Northampton, whose sales bloke, Mark Harris, was great, though we had already decided we wanted one so it wasn't a hard sell!).
We have now had 3 warranty jobs (sliding door window broken on first use, sliding door closer stopped working, new tap). They do the work well, but slowly - they had the van for four days for the door closer and 2 for the tap. This is fine as I'd rather they took their time and got the job done well. Courtesy Caddy was provided for the longest job as I didn't have any family members available for pick up/drop off, though I did opt to pay a voluntary £12 insurance waiver as the excess if I had had a prang with the courtesy car was enormous.
So, in conclusion, St Ives has a Cali specialist, and is recommended by this forum member!