you can just Insert this item to the back radio then Connect the red wire to 12V+, the black wire to 12V-.
match your phone or pad mp3 to bluetooth
module.and Choose Aux from your radio, then you can use your phone to
play music through car speakers.
Condition:100% Brand new
Material:ABS Plastic
Include:1 x Bluetooth module radio stereo Aux cable adaptor
Length:20cm
Fits:
Mercedes Benz E/CLS/SLK 2004-2008.