I have just fitted a set of BMC filters to the C43. I have fitted them to my RENNtech carbon airbox. They will also fit a standard C43 too. BMC make filters for most F1 engines, world toring cars ETC so I thought I would give them a try. The advantage is that they are lifetime filters that can be cleaned. I will never have to buy another set. There is supposed to be a performance gain but it is very difficult to measure. I have taken pics of every step. Standard filters in place Airbox front removed Intake pipes removed. Air box upside down on bench Removed retaining screws. Split airbox in two. Old AMG filters BMC filters fitted Perfect fitment. Fitted.