Yep, the video is the one with 6 holes drilled in the box near the exit pipe - not recommended as it does, apparently, interfere with back pressure, resulting in poorer low speed performance. Munkul's solution is a bit more radical and involves cutting the box, removing an internal pipe and re-welding the box. Personally, I'd still be a bit concerned that it would change back pressure and mess up performance, but I'm happy to be proved wrong. I would play safe and buy a fully tested after market system - look out for a perfect second hand system from someone who's selling their bike. What a pity that Yamaha's engineers didn't design a better exhaust note into the system at the outset - Ducati and Triumph seem to manage it!What's the worst that could happen?