Product review (1 stars): Fix it, don't pay Kitchen Aid anymore $$$
Next time the wheel retainers break, tape the gaps on the bottom of the adjuster piece then glue the wheels back on with a generous helping of JB Weld inside the wheel.  The wheel won't turn, but will slide just fine.  Then, you don't have to pay and reward Kitchen Aid for what must be an intentionally flawed design.  It will get you through until you need another dishwasher that is not a Kitchen Aid.