Wow! I've been using Armorall for over 25 years.
Here in Texas we always have the plastic pads dry and crack on our vehicles but since I started using it, I have never had a single dash pad, steering wheel, or interior plastics crack due to heat or dryness.
The first car I used it on was an 83 Honda civic. And I've owned at least 6 or 7 vehicles since then. Before I retired, I did repair work and drove all day long. Parked in parking lots where the heat inside the car had to be at least 150 degrees or more in the summer.
The only thing that I don't like about it is that it gets on the inside of the windshield.
Edit: forgot to mention. I've never garaged my vehicles and never had a carport...