all i gotta say is thank god i found this post.
i got off work today and the alarm magically decided to arm itself (even though i dont have a master key) and go off. i eventually found the horn and took that out and found out if you turn on the headlights nobody will see the flashing (good way to aviod cops) i was about to go spend $50 at the mbz dealer to get a new master key but i found this post and id rather just disable the alarm all together. besides, who wants a 20 year old 420sel anyway.