This is a hot button issue in the Z community. Some folks say "Noise, what noise?" Others feel the car is too loud.

Do a search in General Discussions, the thread is called "Cabin noise" by RiCharlie. It's long and addresses your concerns quite well. Nissan really tried to keep the Z as light as possible so the car has very little sound deadener. If you find the noise a problem Dynamat is your friend.

Do the search first and then PM me if you can't get the information you need.

Where in Cal are you?