1. OEM (Einspaecher?) $229/335 res/muf, dealer w/bmwcca disc 2. Supersprint s.s. 414/459 " " BMP catalog 3. unknown brand 150/180 " " " " " (does anyone know who makes it?) 4. Bosal ? /359 " Allbmw, etc. 5. Ansa 6. B&B Tri-flo = I have one on my 7 and We tested it with a db measuring device at Idle is about 90db and at full throttle its about 120db. I like the sound, it its a real attention getter. Most people think its to loud.