Don't mean to hijack, but my question is similar enough not to start a separate thread. I'm also interested in installing a transmission cooler setup to keep my trans at an optimum temperature, but my car has to deal with an extreme range of temperature. I live in AZ, and during the summer, the air temperature is regularly 95F+, with frequent trips climbing hills in 120+. I do not have an aftermarket trans temp gauge installed, but just crusing around this summer, the temp on the info center is usually maxed (I think at 197F?). In the winter here, temps get down into the teens. Are there any special considerations for my climate, other than what's already mentioned? The car is a factory-stock 08 GXP with 78,000 miles on it. I've only had it since March, and I've had zero problems with the transmission performance, but the fluid is already starting to turn brown. I want to keep this thing alive. Also of note, when climbing the steepest parts of my usual trip, the coolant gauge does tend to head near the red, even with the a/c off.
