http://www.thedrive.com/flat-six-society/6565/porsche-classics-tire-pillows-make-your-cars-winter-storage-more-comfortable
You got to be kidding. Why not jack it up? I was in the tire business and was a Goodyear Race Tire dealer for Penske Tire. I have been to Michelin, Toyo, and Goodyear training. Flat spots do not damage tires.
I guess these are for people who cannot jack their cars up and put them on blocks or stands. Should we tell them them now they are going to have to deal with suspension set!!!
They have been around a long time. Guys used to pull up on sandbags and rock the car back and forth to let the tire settle in the middle. This way you did not have to take the car off jackstabds every time you wanted to take it out. Then put the car back on jack stands to store it again. Sandbags are cheap "go-jacks" without wheels.