One problem related to other fuel system tank assembly has been reported for the 2008 Mercedes Benz CLS500. The most recently reported issues are listed below.
Strong odor of gas after fill the tank up. The odor was outside, and it eventually disappeared when the level of gas is lower. There was also gas leaking underneath (driver's rear side). I was told to replace the fuel gasket, after doing that, the odor is now inside the car, constant fuel odor, it never disappear. Driving the car is impossible, and gas leaking underneath continues, same spot.