What's this plug...

[ben1.8T]

It's not the brake pad wear sensor is it? That may explain when it appears to have been sanded flat at one side?

Brake pad sensor that big 

Its prob for headlight washers as someones already said. 

[T_J_G]

Ah that's cool then, thanks for all your help guys! Saying that my level low doesn't work on the washer bottle, is tht the sensor that is on the bumper side of the bottle near the bottom?

[Rhyso]

Ah that's cool then, thanks for all your help guys! Saying that my level low doesn't work on the washer bottle, is tht the sensor that is on the bumper side of the bottle near the bottom?

yeah there should be a round hole at the front of the washer bottle as per this diagram (ignore the fact its the 5.5.litre bottle)

[T_J_G]

I'm sure that was plugged in, i'll double check though. thanks Rhys!

[Rhyso]

I'm sure that was plugged in, i'll double check though. thanks Rhys!

no problem  let us know what you find 

[dubcruiser]

Thought low washer bottle warning was part of the "winter pack" but I think it does depend on the year of the car as some have it regardless!!

[Rhyso]

Thought low washer bottle warning was part of the "winter pack" but I think it does depend on the year of the car as some have it regardless!!

yep - got it on mine but don't have the winter pack.  Mind you i haven't heard it since i retro-fitted the larger washer bottle 

[T_J_G]

Mines a late 2000 AUM. My old '98 TDI used to have a warning.

[jtomlin]

mine has a warning, its a 99 AGU and my mates 98 has a warning too, as its broken!

[james2]

i found a plug the same as this down the side of my intercooler and i found were it came from, it was from the bonnet sensor , which tell when you need a service by how many times you open your bonnet , thats proberly why people take them off ... i could be that if you still havnt found where it came from