The subject says it all. I've never owned a manual transmission vehicle with hill start assist, and it's freaking me out. In the owner's manual and the settings, I don't see a way to turn it off. Is this the first Z to have it?
I found it much easier to operate thatn in my Wrangler. I've stalled in my Jeep bunches of times. And been driving sticks for 30+ years now. I will ask one of techs out back tomorrow if there is a work-a-round for it.
Funny story relating to "hill holder". Years ago I owned a manual shift Subaru which had the hill holder. I was teaching my son to drive stick and he was doing very well. Then we came to a red light which was at the peak of a hill on a one lane in each direction road. We were the first car in the line with about 10 cars behind. This also was his first experience with their hill holder. Well of course he stalled the car. He tried multiple times to get going and stalled multiple times.. The final count was that he stalled 25x through 3 light changes!!! I was giving him verbal support and suggestions. He asked me to take over and I refused. He needed to learn how to use the car as it was destined to go to him. ... tough love!