When I was looking for PP or PPP cars, one thing I spotted a few times was that the replacement disks were not genuine PP/PPP items. When you compare the cost to replace, there is , even if you buy from Brembo and not Mercedes (same product) over £1k difference compared to standard C63. I doubt many would be able to see the difference . Just something to be wary of, as the disks on PP/PPP cars are now quite aged, and many start to show smal cracks. For some it will not matter, and the performance differences marginal , but others want an unmodfiied origional spec.