So just a quick update!!.. I got in touch with VWHeritage and explained about the window seals and how poor they were. They have since been back in touch and explained that the seals that I purchased were a cheaper version, but still should not leak. They say that they have a higher quality version, and have offered these in replacement for the ones that are on the car. Well, the replacement seals turned up yesturday and I'm glad to say first impression are good. Instantly I can see there of a thicker quality rubber and feel a LOT firmer. Also unlike like the cheaper version sat in my car, you cant tell where seal is joined. I'll be getting the old ones out and the new ones in sometime next week fingers crossed, so will let you's know how they perform!