 I am the proud owner of this 2009 G37 and so far I love it.  I try to find excuses to go somewhere just so I can drive it.  This car is FAST.  I have to be careful so I don't get a ticket.  I usually keep it in "D" mode to tame the horses and for better fuel economy.  I average about 22mpg in city driving. The navigation and premium packages were well worth the upgrade.  This car is just a dream to drive.