If I lock my A3 Cabriolet with the roof down I can lean inside and steal anything I like and the alarm will NOT go off. The dealership tell me that the roof MUST be up on the A3 for the alarm to work, I find this hard to believe Is this in fact true? The A4 is alarmed when locked with the roof down and so is every other cabriolet (drop top) that I know of.