Even if you graft the F10 gaiter onto the Z4 surround it's still a very tight fit - you need to be careful to not break the larger trim panel where the hazard warning light button is. Worth keeping the F10 gaiter though, it's a bit nicer than the stock one.Although a long time ago there was a thread on here about it posted by someone who removed the F10 surround and attached the gaiter to a Z4 surround.