I had mine replaced at my last service. No questions asked.

This has to be a manufacturing defect. I may have touched this switch a dozen times in two years.

Also an idiot design in that they have to replace the entire switch module, not just the knob!

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2008 4.8i Mineral Green Metallic Sports Package, Technology Package, Cold Weather Package, Rear Climate Package, Premium Package, Premium Sound with iPod adaptor & Sirius Radio, Auto Tailgate, Head up display