My E53 2003 4.6is had bump stops on the upper hatch that required you to spin a lock pin first then adjust the rubber bump stop. I was constantly fiddling with them to stop the tailgate from knocking. BMW subsequently changed to a spring loaded bump stop. Once I installed those two units, the hatch has been perfect since.

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2003 E53 4.6is, titanium silver, black Nappa interior