Has anyone fitted a jcw backbox to their Cooper s? Just wondering on noise difference, sounds, more pops and bangs? It’s for a 2013 R56. Also if anybody knows where to get one from that would be a massive help. Cheapest I’ve found new was on minigenuineparts for £450 but I’ve seen old posts on here from years ago where people were getting them for £300ish. Any information at all would be great, thanks guys.