I guess me and my Z will stay in the slow lane, my Z is to new and I'm getting a little slower. But in reply to top speed for the 370Z, the max speed is electroniclly limited to 155 MPH. I'm not the one to say this is so, but I have read it in several reviews. This is also confirmed by Road & Track in there testing. here is a link:
http://www.roadandtrack.com/assets/d...370z_chart.pdf
155 MPH MAX