A bit of an update for those that are interested. Well since coming back from France and realising the rear seats are a waste of time for me anyway. The Cooper S has gone on a bit of a diet. I have carried out a rear seat delete including the rear seat belts, and removing the soundproofing from the rear trim as well. I have made a rear floor panel and trimmed in automotive carpet. Losing over 20kgs in weight (which all helps on the track ) Rear C pillars have been carbon vinyl wrapped to cover the hole where the seat belt comes through it. A few pictures below showing whats been done.