Just wanted to thank onehundred and the rest of the group in providing all this useful information on the coolant in our vehicles. Right now my SRT6 has mainly OEM coolant (probably the original fluid from 2005) and some recently added Zerex G-05 that I used to top off the coolant about 3,000 miles ago when I lost some during the IC Pump replacement. Reading the website onehundred posted, which states "Perhaps one of the most important elements in your cooling system is the coolant. It needs to be clean, non corrosive, non conductive and have freezing and boiling properties that are appropriate for the conditions. Rule of thumb is to change the coolant every two years.", combined with this thread, I decided it was time for a complete flush and replacement with the Mercedes OEM fluid.

I am a DIYourselfer most of the time, but I want to get it right, and fortunately, my trustworthy mechanic in Vienna, VA, Silver Star Motors, where I took my Merc a few times (Silver Star Motors : 703.281.5606), and his mechanics were willing to agree to work on my SRT-6 for me, at least in a trial run capacity. Peter Fuchs, the owner, is an old school Mercedes mechanic and he was a little hesitant to agree to work on it and had to consult with his mechanics, but he was familiar with the Crossfire's Mercedes origins and so they agreed. The shop is going to do a coolant flush for me next week.

I am trying to think if there is anything else I want done while the car is in the shop. I know I can change the diff fluid myself, and I don't think a transmission fluid change is necessary - but the car does have 40,000 miles on her. What do you guys think?

 

Just make sure they understand about the 2 different coolant circuits, and the shared surge/overflow tank.
Most all Chrysler dealers would just open the radiator drain, then fill it up , and call it a day. I don't mean to be negative, but all the past data suggests that this is exactly what will happen if you aren't proactive w/ informing them of the unique SRT6 coolant flush.