In this forum there are a lot of people with mechanical knowlege: like texas viking
To get rid of this clunky operation park the car always with this procedure:
Drive -> Park instruction
1. stop the car
2. pull the handbrake that it is locked well (do it not like a girl)
3. switch to neutral "N"
4. switch fast to park mode "P" (no time to power rear again)
5. ignition off
This is the only way to do but anyway:
Park -> Drive instruction
1. start the engine.
2. switch from "P" to "D" or "R"
3. open the handbrake
4. bye bye
The problem occurs if you pull the handbrake in "D" or "R" then the drive shaft is under torque and a litle metal bolt locks the "gears" in "P" too fast. But there is a little loose in the drive-shaft to the rear diff. So if the engine is off you have a "negative" torque on the bolt....clunk ...frrom "P" to anything else in the gear box if you want to go away. Suspension and normal brakeing store also energy (low pitch angle). Switch to "P" and this energie comes back to the drivetrain if you open the normal brake padel. I think its more the last one then the loose in the drive shaft
Normaly this have all AT gearboxes on the descant ..the Z has this because the lock bolt is not electronic driven, i think its mechanical driven by the button.. May you have to hold the button longer in "P" but i didnt try this because of the ugly mechanical noise
_ P
_ R
+_N
M_D
-
hope this was helpfull for the AT drivers.. and along life for this amazing gearbox
P.S: For the winter snow drivers this handbrake operation is bad if you dont move the care for some months and there is some salt with water in the handbrake drums before ..they will maybe lock for ever.. so store the car only on a flat surface and open the handbrake ! Or heat it up before stop by pulling the handbrake in winter times a littel bit.