As to the downpipe, I don’t Feel your G35 came with a turbocharger. So, adding a downpipe received’t would you any very good. I Just purchased a 2002 gti mk4 and it by now has a couple of such things as capture can bov in addition to a turbo back https://mylescjpwc.designertoblog.com/59460924/top-guidelines-of-gt-63