I picked up a 2017 A3 e-tron over the summer from an out-of-state dealer. Their ad said the car had Premium Plus and the Tech package and listed the smartphone interface, but when I got the car (and the sticker) I found that the smartphone interface had been deleted, saving the original owner $150. The upshot: no CarPlay for me. Is it possible to add this functionality back? I've since taken it to two dealers in my area and they won't touch it, but AudiUSA will only say "talk to your dealer." I've found various 3rd party boxes that add carplay to MMIs that don't have it, but I can't believe there's much besides the USB harness that's missing from this car since the difference was $150 and Audi wouldn't sell two sets of valve stems for that. Apparently there were a few cars in the early 2017 model run that shipped this way- does anyone know what's actually different about them (or how I could figure this out)? Is the "4th solution" here the ticket (I just have a single USB in the armrest, now)?