IMO, the worst thing you can do to a vehicle is store it which can lead to many failures that have nothing to do with sun, because some store in closed areas and sun is not a factor and still get damage like a cracked dash. Air the same as water can get stagnant because it has moisture in it, water stagnates when there is no fresh water entering. Also possessions in life draw an essence from the life inside of it, one example is when someone dies and their home which may have been in excellent condition at their death.
But maybe because of family discord the house is left abandoned and the house rapidly deteriorates and a couple of years later it is falling apart.
A humans life force adds life to these possessions whether you realize it or not, every time you drive your car and open those doors you exchange air inside the car, so the air on a daily driver does not get stagnant. Also you have an aura about you that extends from your body and that is most evident when someone you do not want within your aura sits too close to you, you get uncomfortable. That same aura extends into things around us the life force so to speak. Our possessions draw energy from that life force around us, because if you remove it for long periods of time you will see degradation.
Maybe if you are forced to store your car over the winter instead of cranking it once a month, maybe increase the interval that you enter the car and completely exchange the air inside of it. Ry
