It is suppose to be a good practice, on cars in general, to turn off the air a few minutes before turning off the car.
This will keep mildew from building up in your ducts, that can result in a foul smell.
I never have done this.
I live in SW Florida and my air is always on automatic, with all the cars I have owned and I've never had a problem.

The auto setting on the G is the only car I have owned that I have to constantly adjust the temperature range.

All my other cars were set and forget. I very rarely had to adjust the temperature setting on them.
The G air comes out as cold or colder then my other cars but does a bad job of maintaining a preset temperature.

 

It's all relative. For example, I leave mine on 72 all summer.. even a 6 hour drive it stays on 72.

Winter is normally 70 or 72.

The system works very well.