Join Date: Mar 2008
Location: Sydney, Australia
I either have the CC system on "full auto" or completely switched off. Occasionally, conditions such as interior humidity caused by occupants' breath etc and some rain [ outside that is ;-) ] will cause the system to turn on to "auto" to demist the windscreen etc. When this seems finished, I turn the whole thing off again or if it looks like it's an ongoing thing, I'll put the system back on "full auto". It actually works very well, imho. I just had to get used to the fact that "off" doesn't necessarily always mean it's going to stay "off".
Having said all that, here in Sydney, I've never actually had to test the system under really cold conditions but it's fine when the weather's hot.
As an aside, on those in-between days, it's great just to have the sunroof open.