LexVan

I pump to about 58 PSI. Car sits for 5 months. Once a month I hand roll the car to rest on a new spot. Final month of hibernation I do weekly. I've never had a flat spot. Been doing it this way for over 10 years. No tire cradles. No carpet/other squares.

Hatzenbach

Or you could move to California, I drive my car all year round :-)