My advice is don't buy it.
My 2012 is an unresponsive dog. It's actually the second G that I have owned, the other being a 2005. (Both bought brand new.) The 2005 was a great car. I loved that car. So much so that I bought a 2012 (both cars bought brand new from the same dealer.)
The 2012 is terrible. Totally unresponsive with a very unacceptable lag. You hit the gas and it just sits there. I've had it into the dealer 3 times for service and nothing has been done about (or perhaps more accurately "can be done"). I've called the Infiniti Customer Service number twice and emailed into the ether once and no-one bothers to even call you back.
If you like cars that are unresponsive and slow - then by all means go out and waste 50 grand on a G37.
But I would think there are far better options out there. (Think Audi, or BMW, or Lexus).
Google "Infiniti G37 lag" and you'll see.
Here's a link to a thread I started 1.5 years ago about this lag issue. The problem persists. Infiniti remains silent on the issue:
2012-g37x-downshifting-under-moderate-a ... 58659.html
PS
I am a car guy. I've done frame off restorations on classic British and American cars. I've rebuilt motors and I've been laying under cars since I was 8 years old. I am not a tire kicker and I am not in the cheering section just to pat myself on the back about my car.
I'm hugely disappointed in my 2012 G37x. I'm telling it like it is.
The thrill of driving my 2005 G lasted for years. Every time I got in that car, I got a bit of a rush. I get in the 2012 and I get angry.