Genuine BMW Performance Exhaust Y pipe from BMW M Performance Exhaust System 135i.
I bought the BMW Performance exhaust brand new but I never wanted to install the Y-Pipe. This Y-pipe deletes the resonator on the mid-pipe and requires cutting. It will make your exhaust sound louder.
The Y Pipe will replace the middle resonator in the car. It will increase the volume of your exhaust and also create some cracks and pops. FYI inside the BMW 1M resonator is just a Y pipe with no perforation.
For 135i, it bolts straight onto your stock rear muffler section. You just need to cut before the resonator and get some exhaust clamps (possible driveway DIY if you have the tools).
Price: SOLD
Location: Sydney (Pick up from Eastwood NSW 2122)
Few links about the exhaust
http://www.bmraw.com/bmw-135i-performance-exhaust/
http://www.1addicts.com/forums/showthread.php?t=1022070