ive been over 140mph numerous times in the 37. no major differences for me between it and my 35. both had suspension upgrades though. as for "tracking", different tires will help solve the problem.

 

I have 2010 G37s and have wind whistling noise from front windshield is present when car climbs past 80 miles. My car is stock and took it just to 100 miles and felt on I5 heading to Seattle it was not super stable, but to be fair this is my first high performance car.

Haven't tried Audi, BMW, Mercedes, Acura or Lexus.

 

I hit 120+ after I launch onto the Interstate sometimes on the way to work.
G is like on rails... Very Stable... Feels like I'm doing 60... It amazes me how stable it is sometimes.