Hi folks. Finally I was able to disable ASD by just unplugging the ASD connector cable from the ASD Sound Module. It takes about One hour and there are no impacts/errors. I have a Hamann exhaust installed and ist sounds really great. Hence I dont need any fake sound in the cabin. It's way too loud with ASD
Here is how:
Turn down the back seat. You have to remove the covers on the floor (the big one) and the left one. You also have to lift the rubber seal a little beat so that you can remove the backplane.
Almost everything is fixed with press buttons which you can remove safely. Finally you can use them again to put everything together.
After you remove the left cover you have access to the ASD module. Just unplug the connector and fix it with a cable strap.
We're currently working on a switch/button to enable/disable ASD from the rear trunk
ASD with the original exhust is fine. But with the Hamann it's that loud that it isn't fun anymore!
However I think BMW should make this feature configurable in the iDRIVE.