On this car we fully upgraded the factory speakers with a BMW OEM HIFI upgrade. We replaced the door speakers and added the tweeters in the door corners. In addition we added a BMW amplifier to amp these speakers and the original BMW subwoofers in the car. It must be noted this system is fully original and keeps the car in a perfect state (no holes / cut wires). We also coded the car with the correct codes to keep any future garage visits a pleasant one.
We use our own in house BMW diagnostic coding and update systems.
In addition to this we fitted an iPOD adapter to control the iPOD from the BMW Business radio, this charged the iPod, or an iPhone, and is controlled with full display feedback on the radio (ie you can control and see iPod features on the radio).