And it will be better than standard navigation
Take broken RNS-D, remove insides and use it is structural frame. Create custom made fascia with the same external dimensions and there we go. I would also check what tablet has best diagnostics software in it.
Do we have Vag-Com/VCDS for iPad or for Android?
Apple iPad Mini in-dash install from Benz guys:
I think there must be a way to hook up rear view camera too.