Just read this article and it appears that the 370z Nismo convertible concept that was showcased a couple of years back is actually a production car...well sort off. Only available in Germany so far it appears to be more of the body kit on the regular engine and it is limited to only 25 production vehicles but I still found this interesting. I wonder why it isn't available in North America.
Nissan 370Z Roadster RS - Magazin von auto.de