The backbox fell off of my focus estate last week so I got a replacement from ebay. I assumed I would need to completely remove the old pipe before fitting the new piece but having done that, the new piece seems to fit really loose like it was designed to go over the lopped off old piece. So now I am wondering how to get the new piece to fit? Should I cut the old piece down and try and slip it back on ( it has a gash down the side though where i cut it loose), or cut the new piece back to where it is thinner and try and get that on? Any suggestions?