Here's some info from JayRash on that other MercedesShop thread: "Any way i have the switch on my C36AMG, when the car is at 90 the scanner will show about 60 C deg if the switch is flicked on, annoying thing is if the car is running and u want the lower reading temp you need to turn the engine off then on. where as if the low reading is on and you want to switch back to normal it will do so with out having to restart the engine."
This is what I wrote back: "Thanks for the tip about turning the car off before engaging the dummy. I was turning the car off each time I changed sensors, but I doubt I would have thought to do that once I had my switch in place."

Just a word to the wise if any of you are planning to do a switchable CTS mod like I am. Regards, Eric