I'm working on a cat-back system for the Mk2. The piping has been done for a while, but I just cannot find a suitable muffler. The first unit I used sounded horrible. I'd still like to go with a polished stainless steel can with twin tips. If you've got a muffler in mind, with 2.5" inlet (or anyone else for that matter), please let me know. Pricing for my 2.5" cat-back, depending on muffler, will run $375 to $400. Cya!