Intro: Aux Input for BMW 325i Business CD
Make your own AUX input cable to connect a mobile phone, MP3 player, Ipad, or any other audio source to your car's radio system. The process is very simple but requires soldering skills at some point. Removing out the radio from the car is a very simple process but not discussed here since there are 10's of video's on youtube showing this process. The pics are very clear showing exactly where to solder the wires and how to connect the 0.47 µF x 4 capacitors. all the process can be made in 1 hour time and costs less than $2.
You can also make hands free calls and hear the audio from your car's speakers with superb quality.
Note: The Iphone's original socket has 4 pins, the forth pin is for video wich is not needed in our case, here we used a clasic 3 pin stereo socket that plugs into most devices including Iphone with no problem. So just use a normal 3 pin stereo socket as in the pics.