I was following this thread a while back because I have a long commute on a mostly concrete freeway, and on 20's the road noise is maddening. I paid a shop to completely blanket the interior in a Dynamat-like product, as well as some foam layer, but it made little difference with the road noise. I ended up spraying Second Skin Spectrum in the front wheel wells and that did the trick. The strut towers used to sound tinny when you tapped on them, now they sound solid.

 

i got an optional silencer I put it on, zero drone, quieter exhaust without sacrificing exhaust tone. I can take it off on selected days for spirited driving but for daily driving, silencer is on.

 

For "entry level luxtury" the G37 has a LOT of road noise. More noise than my 99 Altima.
I hope my Stillen exhaust will replace the "road roar" with pleasent sounds.