I have also noticed that since my BMW dealer changed my ATF Fluid, on my request, my problems started.
This gave me the idea that the filling process in the factory might be different then somebody outsite of the factory can do. I'm thinking in the direction of filling under pressure/vacuum, minimizing things like the amount of oxygen in the box.
Might be an incorrect thought, but maybe usefull to share.
BMW 335 E92 08 - Full options - RIP
BMW 335 E92 09 - Full options - DKG - Procede Rev 3 - Vishnu Meth and Chargepipe - Forge Diverter Valves - Vishnu Flex Fuel Kit- AR Catless DP - Afe Intake - Helix IC - Ar Oil Cooler - PPK Water Cooler - M3 Suspension - JRZ RS1 Shocks - Eibach Pro Springs - Drexler LSD - BMW IS Exhaust - EBC Yellow Brake Pads - Stainless Steel Brake Lines - M101 Wheels - Michelin PSS - M-Tech Body - M-Strutbar