I just finished up a little 4 hrs road trip in my 2006 e55. After dropping my cell phone the was sitting on the passenger seat, I noticed that the passenger side of the transmission tunnel was pretty warm to the touch. The drivers side was cool as could be. I've never noticed this "hidden feature" before. Is this typical?

My trans tunnel gets warm. After 4 hours the trans was probably pretty warm so that is normal. Mine gets extremely hot after 40 laps at Road Atlanta.

What's the rear a/c temperatures set at?

I wasn't running the AC during the trip. Temp in the car was set around 71