Hello together I have a problem with a minimum air loss on the tyre / rim on only one of my BMW 668 20 inch rim and I just can’t get any further. The pressure loss is about 0.1 bar within 2-3 days. I have already done the following: 1. Tyre pressure sensor: I have replaced the sensor twice. 2. Leak search: The tyre has been placed in a water bath as well as examined with a leak search spray – both without success. 3. BMW garage and tyre w erkstatt: I was in a BMW garage as well as in an independent tyre workshop. Unfortunately, no leaks could be found there either. 4. Valve and rim: Visual inspection revealed no damage or abnormalities The tire is otherwise normal, and there are no visible damage visible. Could it possibly be a hair crack in the rim, or are there other hidden causes that I should have tested? Or someone already had experience with such a thing?