I imagine that fitting this would be no different to any other after-market HU. If you were to fit this, you would likely need all the usual after-market HU adaptors to make it work with whatever flavour of Audi speaker setup you have.
I remember fitting a double-din unit to my old 8L S3 and all of the Bose and amp quirks just got in the way. In the end, I replaced all of the speaker wiring, the speakers, the amp and the sub in order to get it sounding right. I used a Kenwood HU at the time. Being an outspoken Android fanboy, I wouldn't bother with CarPlay personally , but would be interesting to see this in action if you were to fit it..