Hello, and welcome to NICOclub!
I will move your thread to the G37 forum to get more platform-specific eyes on it and input from other G owners. We do the same in the M forum - some tires seem to work better than others.
... I'll leave a shadow topic here as well. Someone might have some good feedback or pointers such as dealing with Tirerack.
The AWD is outstanding in my car but it doesn't do any good without a tire that can keep up!