Hi Rob, I ran into the same issue regarding the exhaust flap last year in November at around 40K miles. I have an 09 TDI sedan. The dealership said that the part is not covered under warranty and will cost around $500 to fix. I spoke with another Jetta TDI owner with around 40K as well who ran into this. If possible, it was recommended to just clean the part instead of replacing. Hopefully this doesn't need to be replaced every 40 - 50K....