Thanks for the info Transporter. So that explains why all car manufacturers require their cars to be serviced in shorter intervals if the car is subject to lots of idling, because the oil goes to crap quicker!
Yeah, I turn my car on, and as soon as the idle has dropped from ~1000rpm to ~700rpm, I gently drive away. As far as I'm concerned, you don't need any light - that's how VW is letting you know the car is ready to drive away :)