Nope, I do the same. The noise you hear when shutting the car off is the flywheel tapping against a spring which in these cars IS NOT a bad thing. Do dual mass flywheel research and all your questions will be answered.

 

agree.. i think that it is the flywheel making that sound w shut off. I bought mine in x 2 to infinity just to get different mechanics opinion and they both said "its absolutely normal with a two piece flywheel design"
If you are overly concerned just have them place in your record. As long as performance and / or clutch is functioning normal it should not be an issue. Several mechs have told me that (to their knowledge) there has not been 1 case of failed or blown out clutch on any G35 / G37 and its just a simple 2-piece flywheel / pressure bearing design that (unfortunately) makes this noise. Really it should rest on Infinity corp to rectify this and develop a "noiseless" flywheel design. I really think that everyone should just take a breather and deal with the noise...

 

I had this same noise on my 335 Sedan Manual and was told it was normal as well.

 

Same sound, I never thought of it as an issue. When I had a G35, I had the same sound too.

It's normal, and I also turn off my car in neutral and then put it in 1st; no issue as someone else pointed out.

 

I was just about to say the same thing, my friend brought his 335 coupe in because of the exact same noise and the BMW techs said its normal. So when I heard it on my G37 I didn't really think much of it. Don't worry about it.