Yesterday was the first autocross of the season, and the first one in the NISMO (I did a couple races in my old Saturn Ion Redline, but that was probably 7-8 years ago). It was a blast! The annoying thing was that there were probably 175+ cars racing, so it took forever!
And I can confirm what everyone says about oil coolers! I didn't look after my 2 morning runs, but after my 2 afternoon runs, my oil temp gauge was sitting right at 220.
I ended up being pretty slow compared to everyone else, but seeing as how it was my first race with the Z (and in 7-8 years), I wasn't expecting much. I think my problem was that I was trying to go too fast and not braking enough before the turns.