Like VALK, I too add only 8 quarts of 0w40 Mobil 1 European Formula motor oil during a scheduled change along with a "fleece" oil filter element. And with this process, no issues.

I did attempt 1x to add the 8 liters that is actually the correct amount of oil for the oil change on the M-B 3.2L V6. This calls for about another 1/2 quart (0.45 qt to be exact) beyond the 8 quarts. Like most folks, I probably added an extra 0.50 quart of oil - ever so slightly over-filled. Performed this oil change right before a Dragon weekend event. During that weekend, while driving around on those twisted mountain roadways, the HI level indicator came on several times. Seems like whenever the car forced oil to one side of the oil pan, the HI level warning light went off. Came home & removed about 1/2 quart of the oil I put in. Warning light never came on again.

For those that had the warning light come on, do you recall if you were taking any turns aggressively enough to force oil to one side of the oil pan? That would trigger the HI level indicator if the amount of oil near the sensor was excessive. An engine oil system with 8 liters added during an oil change could do that with some aggressive driving - ?. For me it is hard to understand why you would be able to drive for several thousand miles w/o any HI oil level warning and then all of a sudden, you have too much oil in the car. Doesn't follow any logical process. Something specific is happening to cause the HI oil level warning to come on. A bad sensor - definitely a possibility. Oil level high near the sensor - definitely a possibility with some aggressive driving style & an oil system with 8+ liters added during the oil change. My $0.02

Just thinking out loud. Some folks put 8 liters in w/o issue. Some have issues with 8 liters added (which is hard to get exact in the non-metric world). Quite a few of us (in the non-metric world) use 8 quarts w/o any issues whatsoever.