We spent a lot of time dissecting my Cayman with
Mods4Cars chief developer and a
PIWIS machine to see if there was a way to alarm chirp with
PIWIS and there was not. What they literally had to do was make it chirp and capture the CAN BUS hex code that was issued to the control module to make it chirp and then program that hex code to issue when the code that comes across the can bus stating that the doors are locked (a different code) is received by the control module.
Remember you can always enable/disable the Mods4Car module so that a dealership cannot even tell it is there and basically it isn't, it is listening on the CAN BUS but not replying so it isn't doing anything unless it gets the signal to wake up and go active again. Right now
Mods4Cars is running a group buy, a good time to pick up their module.