Uhhh… seems to be really a lot of work for you to make your cool skin work with Kodi 17. Could be a pain in the ass. So, another solution could be, to install Kodi 15 under Raspbian – just to be able to use your skin.
If you can manage it to make it work with Kodi 17+ it would be really cool and of course I would pay for it!
Yes, the A6 4F uses more bus-topologies. As already mentioned, 1 CAN-Network for the engine / drivetrain, 1 CAN-Network for Comfort-Functions. These are normal twisted wires CANs.
The optical MOST-BUS is the multimedia bus – only for controlling and monitoring the multimedia-devices like radio, TV, CD-changer, AMI and so on – and for transporting their multimedia-contents.
MOST- and wired CAN-Bus get connected in the CAN-Gateway.
The A6 4F Facelift (since 2008 / with MMI 3G) got rid of the MOST-Bus. It uses the wired CAN-Network for exchanging multimedia-contents. I don’t know, why they dropped the MOST… perhaps the production was too cost-intesive.