Does anybody use tire cradles?

I have a set of tire cradles that I purchased when I had my Carrera because if I parked it for a long time I would get a terrible shimmy in the steering wheel for the first half hour or so. These things prevented the flat spot and I noticed I would not get the shimmy anymore.

I have been using them under the Ferrari for the same reason.

They can be a little annoying because they will move sometimes after using the car and lining them up can be a pain. Also if you move the car out of the garage they sit on the garage floor and interfere with walking or moving motorcycles or toolboxes.

Does anybody get a steering shimmy? I've been using them so long that I don't know if the newer tires flat spot as easily. If you do get flat spots you should check them out.

http://www.tirecradle.com/tcradle.html
PS I have nothing to do with this company I just like the product.