This is a fictional Art Car skin for the BMW M4, including Akrapovic. You will need to copy the skin folder to the Akrapovic model if you want it on it.
Original Art work by Abstractmix: http://abstractmix.deviantart.com/art/theleftovers-Wallpaper-37459733
Original Art work by Abstractmix: http://abstractmix.deviantart.com/art/theleftovers-Wallpaper-37459733