Hey. I think it should already be possible.
http://www.autoradio-adapter.eu/blog...
I've found a page for you, but I don't know if this is exactly your car. I'm more of a fan of Japanese cars than German ones. If you have further questions, go to a vw polo forum. E.G. http://www.polo9n.info/Wissen
I hope I was able to help you.