Is the brain of your C4 a bit flaky? it is on mine (55 plate Diesel VTR). every now and then it will suddenly decide that one or other of its functions is no longer working, and it need to be immediately taken to be serviced - this scared me the first couple of times, but I have found if you just turn off the function concerned and turn it back on, all is OK. I think the brain must have been programmed by Microsoft, and just needs rebooting every now and then! The 2 favorites are the speed limiter /cruise control not functioning (you just flick it off and back on again a couple of times and it is fine), and the temperage guage suddenley jumping from normal temperature to massively overheating instantly! (you have to turn the fan on and off again to clear this one!) Anyone else get this, or is mine 'special'?!? :(