I've noticed lately that on these very hot days the temp. gauge on my M3 will creap up to around the 3/4 mark when sitting in traffic (long red lights,etc.). It's never gone past that but I think that's only because I start moving again and it'll come back down to just past 1/2 mark. The switch on the front of the thermostat housing is not connected to any wires, I've recently discovered, so that is the reason the auxil.fan doesn't come on - Right? although it does come on while I'm running the a/c so it does work, just not fast enough to keep the temp gauge in the middle. I've read that the aux.fan has two speeds and also remember someone saying that they had hooked up a toggle-like switch inside the car to activate the fan on high speed in hot situations. This sounds to me like a very good idea, has anyone on this forum done this and if so, HOW? Thanks in advance for any info that you may have..