I love my eisenmann race set up. My install was about 1.5 hours. The sound really breaks in at about 3-4 weeks. Drone can be annoying sometimes but compared to stock 550 set up totally worth it. I would not want anything louder. Race is the way to go. Still classy but just loud enough when you get on it. The best is the sound of a cold start. Enjoy!
BMW 550i F10/Vossen CV3's/H&R Springs/Dinan S2/Eisenmann Race Quad Exhaust/JL Audio