That's the way I understand it but it doesn't work on my car. Would you mind trying it again for me and let me know what you did, I'll try exactly the same on mine.
Not sure if you mean the "Car Settings" menu? I checked that it wasn't turned off but you can only choose 30, 60 or 90 seconds, no off setting. I did try changing it from 30 to 60 secs but it made no difference.