Mercedes SLK 350 2004 model here for an audio upgrade. We installed the Sony XAV-AX3005DB and we used the Connects2 fitting kit to complete the installation. The fitting kit provides the fascia and a steering wheel interface which retains the volume controls on the steering wheel. Customer now has Apple CarPlay, Spotify, DAB, Bluetooth all at a touch of a button.
End Result a very happy customer with a better sounding system in his vehicle.
If you require something similar please get in touch.