My install is very similar to the M3 video except I went down the driver side. I had installed a Dice Mediabridge many years ago so I knew that route would work and be factory like.

I have a Seicane unit that I don't recommend because of total lack of customer service. But from going through the problems of that install I would never even suggest trying to customize the unit features unless one is a pro. My view is to buy something that already has the features you want and one you won't be breaking new ground. I think Android based is the only route to go. At least there is half a chance of keeping up with emerging factory features that might come available as an android app to stay state of the art.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas