GT TDi 170 - What does this button do?!?!

[nivek]

My friend has just taken delivery of a brand new GT Tdi 170 and just in front of the gear lever are two buttons. Now one is the ESP button but the other one has a 'W' on it and a light.

Now pressing this button doesn't seem to do anything to the car?? Nothing lights up on the dash and I don't think it for the tyre pressure sensor as another friend has a R32 and that button has got a picture of a tyre on.
 
Does anyone know what this button is for??

[wantmygti]

I think I read in Evo managzine that this is the Winter mode button, which reduces torque levels being put down when roads are wet/icey/slippery.

[Mk1Mad J - 16v]

Thats the self destruct button 

  when I was a kid my cousin had a beetle, he told me the hazard light switch was the self destruct - then he'd scare the sh!t out of me pretending he was going to press it  I was young, i knew no better 

[nivek]

Although I like the idea of the self destruct button  I think wantmygti's answer is the correct one!!

Thanks for your responses

[davidlandy]

if u use the W button you can notice the difference when pulling away - you need more throttle to get goin

[The Doc]

This...