Here is an article about the problems with the VW and product that was developed by VW request, it is what is being used at dealerships. The wholesale cost of the kit is about 85 bucks pluss the cost of filter and oil for 3 changes I think. Never guarantee anything, caution customer of some of downsides and on the work order put preforming at the customers request not you recommendation.
http://www.bgprod.com/blendr/stickyProblem.html