Ive got a problem with the gauge dropping to cold instead of sticking to the middle. Accelerating hard seems to initiate the problem but other then that theres no pattern. The needle will drop, sometimes to the bottom but sometimes only slightly, and then will rise again sometimes to the correct position, sometimes to only 1/4 way up.
The car is at the dealers now for the second time with this problem - in december a new coolant sensor was fitted which cured it until 2 weeks ago.
Seem to remember some other people with this problem and wondered how it was fixed for them.