[elav]

I went down the same path - got everything working and still had the double beep (and the alarm would go off for no reason every once in a while). I replaced the ignition switch and the double beep went away and no faulty alarm every since. May want to replace it and cross it off the list. The Audi part is cheap - so why not?

Originally Posted by KevinH1990

http://986forum.com/forums/boxster-general-discussions/12094-horn-beeps-twice.html

This thread suggests that the problem may be caused by a wiring issue in the top latch.