GBMINI has been at MINI Peabody for a couple of days – the primary task was to install the factory alarm (a little more paranoid with the recent John Cooper Works upgrade. The only visible difference is the red tip on the end of the wiper control:
Alarm installed in GBMINI#2
Alarm installed in GBMINI#2
It is apparently controlled by the normal remote open/close – there is no instructions!?
M&I / GBMINI 
I’ve considered an alarm — factory or after-market, I don’t know. Is it terribly expensive?
The factory alarm comes in two versions for different model years, between $300 and $400 for the unit. My installation cost $90 on top of that. Reasonable for a fully integrated system that does not need a second remote.
The wiring is already present – though I am not sure if that is true right back to the 2002 model year.