Has anyone been able to upgrade a Tahoe to add the ZM1 feature, or at least support for the Trailer cameras for a vehicle that was manufactured without them? I picked up the vehicle last week. The salesman showed me a vehicle with the camera connectors but the one that was ultimately ordered does not have them. I would have been willing to wait on delivery for 6 months to get this feature. The Tahoe has Supercurise, so it is possible that only the camera wiring harness and connector is missing.