Recently my 2007 CLK 2.2 has started to go into alarm a minute or so after I have parked up, armed and walked away. When I disarm & rearm it all is fine.

Today however I haven't used the car, but I did open it to put something in it, closed and armed it and a minute later it burst into song! I disarmed it, rearmed same again, in alarm. The third time it worked and peace was restored.

Advice please, as I see a potential problem should it start to go into alarm during the night!

Thanks!!