If you don't like weird noises and rattling the GTR may not be the car for you.
I swear both my GTRs were/are ready to explode (not in a good way) every time I get behind the wheel (especially driving leisurely) but they don't.
Though you should still buy one. It's acceleration is something else.
-2011 Cayenne Turbo
-2012 Cayenne Turbo
-2013 VelociRaptor 600