What does this button do?

[PeterHBne]

Interesting. If you have the car locked with the windows down, sticking my arm in the car is enough to set the alarm off. Very loud in my car park...

If you wave your arm at mine in a still space or a small bird stirs the winds, the alarm goes off. Very effective. As you say, LOUD.

[seangti]

I thought the double lock armed a dead lock os soemthing to that effect, like in the Holden Astra. Basically, you can't unlock the door from inside when the deadlock is armed... that's for the astra so maybe the VW doesn't have such a thing.

[Roodosutaa]

I'm pretty sure VWs have the deadlock function but you don't get the option of not engaging it, ie once the alarm's on the deadlock's on as well.

[Tony_Mitchell_1983]

I don't know why but my car doesn't make a sound when the alarm goes off.

I know because I threw a jumper through the sun roof once while the car was locked, and the lights started flashing, but it didn't make a sound.

Odd...