Original great condition 135i PE with Y pipe, and clamps.
Bolt on solution to any year N54/N55 135i. Also easily adaptable to any year N51/N52 128i, with some welding or using a step clamp.
Detailed photos:
https://photos.app.goo.gl/mBRfT56CKco5dFQe8
One of my older 128i idle video clip for sound comparison purposes:
https://photos.app.goo.gl/CBnix5Hw5CeG1g6z9
Please PM if interested. Check Itrader feedback. Always verify user name when PMing. Thank you.