I spoke to Audi North America and Audi HQ. While they both agreed the design was faulty, they returned to manual intake control versus vacuum control, and they never did a recall. The parts are fairly poor plastic and will never hold up to the heat of the engine long-term, but there are no third-party or after-market solutions. Audi recommended a full intake manifold replacement, which includes replacing the vacuum unit with manual. That is a $3200 part. This is a poor solution, so I searched salvage yards and every after-market company in the U.S. One called me back to say he located the part on a shelf out of inventory. The part arrived yesterday ($450 USD), and I dropped it off at the shop. I am hoping to have the car back in a couple of days.