Hiya folks. Sorry, I don't have a 370Z. I have a 2009 Nissan Maxima, and over on the Max forums, many of us have the exact same issue. We were provided a link here and figured I'd return the favor. You all aren't alone in the "rocking" issue....
I've taken mine in, dealership noticed the issue, replaced the whole seat frame, and yet, same issue.
My first problem. - Page 3 - Maxima Forums