I had an alarm retro fitted to my 2014 GSA. Worked fine , but I found not having a keyfob a pain , so bought an RT one and dealer programmed it. Alarm will go off if you just open the topbox when on the centre stand. However if you have the keyfob. Press once to arm the alarm , but if you dont want the motion sensor (On ferry or train ) then the press the arming button on the fob , Twice !