The CoolStream Duo will ONLY work with the 2009 Mercedes SLK350 if the iPod cable also has the 3.5mm AUX jack. This is a specific cable split in two, with one end having a 30-pin iPod connector and the other end having an AUX port.
The 30 pin connector on this iPod cable will give the Duo power. But the music has to go through the AUX jack.
As soon as the car is turned on, the Duo will power on. It will automatically connect with the last phone that it worked with. All you need to do is press play on your phone.
The CoolStream Duo will NOT work with the remote controls on your steering wheel. The music will automatically pause if you get a phone call. If your car has Bluetooth for phone calls, this will still work. The CoolStream Duo is only for music streaming.
This cable in this vehicle is also compatible with the CoolStream CarPro. If you are looking for more functionality, such as a music display on your entertainment screen and access to the steering wheel controls for pause, play, track forward, trackback, and volume control, we recommend the CoolStream CarPro.