Dear,
Thanks for contact us and apologize for the late response.
yes, this unit can fit your car perfectly.
you need buy this Decoder MOST box to work with harman kardon system.
https://www.seicane.com/2005-2012-mercedes-benz-ml-class-w164-ml280-ml300-ml320-ml350-ml420-ml450-ml500-ml550-ml63-car-optical-fiber-decoder-most-box-bose-harmon-kardon-converter-optic-interface-sc69
there is no need anything Other, we will send all needed cables to you, it is plug and play.
yes, it will work with your backup camera.
Instant payments are very important; the earlier you pay, the sooner you will get the item.
Please feel free to contact us, we are always at your service.
Looking forward to your purchase.
Have a nice day.
по
Seicane