Kriesegg exhaust on a TR.....!

Oh My Gawwwwd...I was in the fchat showroom section concerning exhaust systems and followed the link to Kriesegg. I never thought a Testarossa could sound so mean! You should check out their video clips, very impressive. Most aftermarket exhaust systems on a TR sound nice with a very deep and gutteral tone, but to hear an F-1 sound out of a TR is amazing. They also have a lot of pics of the system from different angles and it's truly incredible! But with a cost of over $9,000 it had better be. I would love to know their secret to getting that "shrill" sound they get from a 12 cylinder motor. I would imagine it's due to some apeture size or baffle shape, or a combination. I'm currently working on an "off road" exhaust system for TRs and would love to get that high pitched sound. In my opinion the F-355 has this sound, although a bit more subtle, in stock form. I've heard 355s at the track with the factory muffler in place and they sound very nice when winding it out. I would like to mimic that sound, only quite a bit louder, on my TR. If anyone has some insight as to how this could be done I'd appreciate it.