Update, car went back to dealer this morning, the problem is the rear amp is faulty. there is a world wide back order on these amps and it's going to take a few weeks to get a replacement. Apparantly these are new amps in LCI models so older amp will not work.
Dealer has disconected rear amp so at least nothing will come out of rear speakers to disrupt the driving expirence. Probably means no subs either!
Annoyed that I won't have the full car I ordered for another few weeks. I guess I'll just have to listen to the exhaulst note for a while until they fix it.