I have an 2011 G37x sedan and when I floor it in first gear, I notice that there is a lot of smoke when I look in the rearview mirror afterwards. Is this normal or is it just because of the weather which is 30-40 degrees F. I also don't think it's the tires. No screeching, rubbing, or jumpyness. So I feel all of that is from the exhaust.

 

Has the vehicle fully warmed up, if not then it's not uncommon, otherwise depending on color and amount of smoke there may be cause for concern.
Here's a link explaining what to look for
Tailpipe Smoke | Car Emissions - Consumer Reports

 

Warmed up for 20-30 minutes. As for the color of the smoke, its normal white smoke that comes out out of most cars when it's cold outside. The amount of smoke is like a mini smoke screen that quickly dissapates. Could it be from burn off carbon? I've had the car for a few months and have not pushed it as hard as my old car. This reminds me of a time when doing seafoam to my car and my mothers car. My car, a significantly older car than my mothers car had a major difference in the amount of white smoke that was put out(her car significantly more white smoke). I believe it was due to amount that I pushed my car (often redlining) compared to hers(not so much).

 

Do most cars give off smoke? Are you sure this is smoke and not vapor from condensation?

 

Oops... vapor then. Think of your car starting on a cold morning and the vapor coming from the exhaust while idling and now multiply that by 10 times and thats the cloud left by me after a take off in first gear. It's not a trail but a cloud such as if I were sitting in one spot and revving the engine.