I have a '17 35T with a failing thermostat. It takes ages to warm up fully. The temperature gauge goes up and down as I drive. Classic symptoms of a thermostat stuck open. I called all the Jaguar dealers that are even slightly close, 2 hour drive or less, and the soonest anyone can service the car is the end of January. So I'm going to take it to my local independent garage. They're excellent and I've used them for ages, but they're primarily a BMW specialist and don't see too many modern Jaguars. Are there any non-obvious things about changing the thermostat that they need to be aware of?