I have the shuddering issue on my 2016 A8 car and I'm having my tranny flushed in a few days. Meanwhile I bought the
Range AFM disabler OBD dongle that does just that. It disables AFM altogether which means my car always runs in V8 mode. Funny thing is I haven't had any shudder since I installed the dongle a few days ago. I'm still having the tranny flushed under the TSB service while my drivetrain is still under warranty. I will take the Range dongle out after the flush and drive the car and see how the tranny behaves. If the shudder rears it's face again, I'm going to insist on having the torque converter replaced while the car is still under warranty......
I think it's ironic how a $190 OBD dongle can magically make the shuddering issue go away but yet GM insists on doing things the hard way....