2009 CTS4 Premium & 2012 SRX4 Luxury
With 67k on the car, there was quite a bit of carbon buildup on the stock exhaust tips. When I first looked at them they appeared to be relatively plain single wall slash cut tips. I was surprised when detailing the car to discover that the factory tips are double wall Corsa-style! It took my Dremel tool with a felt disc and some polishing compound to clean all the crud around the inside lip, and alas there is some pitting on the bottom edge where moisture runs out. I notice there is a perforated baffle inside the tips but no drain hole in the outer wall underneath, so it has somewhere else to drain. After driving around a few days later there's already fresh black buildup running out. Any tips on how to keep the factory tips clean?