Has anyone in the San Antonio or Austin area done a walnut media carbon cleaning on the intake valves on a 2.0 engine. My 2015 Audi A3 Quattro (very similiar engine to GTI 7-7.5 and Golf R 7-7.5 i believe) has 110k. I bought it about 2 yrs ago with approx 52k miles on it. I've been good about...