Maybe its just a regional thing, but I live in North Carolina and when I see roof racks (usually Thule), they are generally perched atop Audi's and VW's - occasionally BMW. Age is usually between 30-50.
Is this true where you live too? Of course there are exceptions to this "rule". I just wonder why in general people stick their bikes atop German engineered vehicles? Maybe its a monkey see monkey do type thing but it just seems to prevail.