Guys a quick update, here is the x-pipe I used and I'd be having manufactured, notice the step increase in diameter in the center, for sound and flow it makes a difference. I can't sell them yet, but if I had to assume a fair price I would probably do $60 + shipping. If their is interest, please respond, and I will become a forum sponsor and could start selling and shipping within two weeks.
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6 series - Sapphire Black w/ 22" Beyern Mesh wheels