I work for an Audi/Vw dealership, and I see "chopped" tires all the time. Before working here, I hadnt even heard of it. Basically, "chopping" is when the outsides of the tread becomes wavy. Often it is visibly wavy, like 1-3/32nd different in depth.
Almost every time I look for it on a car up in the air I can find it. Maybe its a VW thing, but it seems odd how much I see it.
So what causes it? I thought maybe it was the slightly stiff factory suspension, but then why dont you see it on cars with modified suspension..
Also, these vehicles are un-modified, 20-50k mile cars, usually driven by middle aged women.