Thought I would update this. When the rear bush came I really didn't like the way the offset bush was fitted. I think it would be very very difficult to fit this in exactly the same position either side, I also think it would rotate when you tighten it, in essence I think it wouldn't be almost impossible to ensur both sides are equal. I contacted Powerflex and they sold me a standard insert so I now have the antilift feature but without the castor adjustability, the non offset insert is interchangeable with the offset castor bush so you can get the antilift feature without the castor but you would need to go Powerflex direct as they don't offer it as an option just now. Its a shame but I think it would be a good product if they made the bush serrated and the insert serrated to match so that you can select the position and known it won't move. It's hard to get a castor increase so definately scope here for someone to make something. The same could be applied to the font bush in terms of camber but again it needs to be able to be set knowing it won't move and at the minute I know of a few people with track cas who have had movement in that bush.