My B6 170 Sport Manual Estate was ordered with the optional Tyre Pressure warning light.
The idea is that if one of the tyres develops a puncture then the difference rotational speeds will be sensed(maybe by the ESP ?) 
and the warning lamp should come on and a 'bing' audible warning sound 
to warn you that all is not well with the tyres so get your self in a safe position and investigate ! 8) I have always had a problem with mine; If I happen to stall the car
and I restart the engine very quickly to get out of a tricky situation 
then the light will come on and stay on no audible 'bing' this time.The light will stay on permanently while driving
and the only way to get it reset is to take into a VW Dealer who reset it with their computer. 
IF and it is a big IF I can after stalling it, I take the key thing right out wait a second or two then start again then all is well. I very rarely stall it these days except the other night when some drunken idiot staggered out into the road !
I stalled it and got it going damn quickly, 
don't worry I didn't run over the said drunken idiot.Has anyone else had the warning light come on after stalling ? VW are aware so my dealer tells me
Thankfully I very rarely stall it now !!
Regards
Shady Blue Two