I posted a similar thread not long ago, I drive a MK5 GTI so different to yours, my car goes through a lot of engine oil with no sign of leak. I was advised the amount I was going through, about 4-6 litres in a year was normal. I had mine checked by VW as well who said all was ok.
You however have a different car and are seeing a build up of oil so I would imagine that there may be more of an issue here. I would get it checked out to be honest mate for peace of mind. Find out what decent garages are near you and have them look at it.