On the switch-over valve is you will attach a wire harness with a plug that has a long 2 wire lead. this lead goes to the DME behind the bose speaker sub woofer.One wire is Grey/Green, the other is Red/Blue. Cut the grey/green wire near the dme giving yourself enough room to work. Get a 2 pole toggle switch or equavelent and soldier a wire to each pole. A good place to install the switch is in the ashtray. It is very easy to run the wires under the center console to the dme. You can hide it completely without removinig any other pieces. Now solder each wire to the wire that was cut. You are completing the circuit by going through the switch. With the switch off, you are disabling the circuit and causing the sporty sound through the entire rev range. if the switch is on, completing the circuit, you will have your standard setup, ie the sport switch under the psm screen controls the exhaust. Keep in mind that my car is a 2006 and has sport chrono pkg.