I have done in some E60 and X3 without any problem.

Never did a z4 but it shouldwork...Do you have progman?

 Never did it either, but did you try clearing the code before doing the calibration?

Did you receive any prompts when failed? For this kind of problem, datalog will be more helpful to locate this problem. If it is convenient for you, we hope you can send us the datalog for our analysis. Thanks.

 did you get the unit programmed???

 For older bmw's like E38, E39, E46, E53 and possible E85 you have to choose the car manually to code the DSC unit. I had 2003 BMW E39 530 USA Market and if I read vin automatically it only shows me in codings ABS with ASC stability control, after manually choose E39 540 it allows me to code DSC III system and everything went through. Autel has incorrect win option decoder. I hope it helps.