I got a half day. That is what I asked for. I got it alone too. It's well worth it. I was going from a 4 door saloon so needed to be sure I could cope! Got an S2000 too, got a half day accompanied. The sales girl was hot and really nice too. She didn't try to sell it as I knew more about it than her.
Ask in advance to book an extended test drive. If the Nissan dealer won't let you then call NMGB and ask them.