Welcome! Noise or not, you will love the car so much during the first few weeks or ownership that you won't be bothered (much) by the road noise. A few things to note:
- Transmission whine is intense when the car is new, but this diminishes within a week.
- The most road/tire noise appears to come from the rear wheel-wells, which are a mere ~2 feet from your head.
This week, I decided to DIY some insulation in the interior of the hatch, and I ran it up over the wheel wheels, and even up the back wall of where the hatch meets the trunk.
I used (don't flame me) industrial black rubber underlay that's used underneath laminate flooring - specifically designed to reduce noise between floors. I fixed it in place using Gorilla Tape, and sparing amounts of rubber (contact) cement. Easy to remove should I need to later.
The results were surprisingly good. All of the higher frequencies while driving have been decreased substantially, and only the lowest bassy-rumbles of the exhaust make it into the cabin. In fact, I notice much more sound comes from the front of the vehicle after this DIY test.
It's not Acura TL quiet; the car will always be a little loud inside. But the harsher sounds, the ones that interfere in the frequency range of speech, are pleasantly attenuated.
That's right: "better-half friendly" stuff!
A little elbow grease, and some half-decent sound-deadener will go a long way.
Then, new tires.
Enjoy your Z!