Joe... I use to do the ol' tunnel runs with the Scooby... although, mine was standard so wasn't very loud, but great fun all the same! I just use to release the dump valve more regulary as we went through the tunnel
Its fine about the exhaust, it was just a thought. There is a good exhaust "specialist" near me, and I am thinking about going to see him, to see if he could "add" the twin exit to my existing exhaust. I only want that, as I am fitting a GTi rear valance, and it has the cut out for the exhaust.
Any pics of your MKV yet?