I have a 96 a4 2.8 with an aftermarket alarm. Usualy when I hit the arm button it locks the car also. but only my alarm will arm leaving my car unlocked. It didnt happen abruptly but over a week or two of working then not working. before I could lock/arm my factory alarm by locking the driver side door now i have to use the passenger side door for that. so im sure its not my afermarket alarm but my central locking system. any ideas would be great! thanks for your time