Reading this thread I'm glad I own a spring 2015 vintage P85DL.
It would have cost Tesla at least a couple hundred bucks extra per car, but what I think Tesla should have done was sell early AP2 cars with both sets of hardware, leaving an EyeQ3 in the mirror housing, which would share the medium-view forward camera's feed with the AP2 hardware. Obviously this would be a major hardware kludge, but I can't believe its implementation would compromise the AP2 hardware that would be included. Then AP1 functionality would run on newer cars, and owners of those cars would have nothing to complain about: their cars would still be future-proofed. AP2 software could then be developed at Tesla's leisure, where alpha versions would be running in the background for software development and to compile fleet learning. When AP2 software was finally ready for prime time, Tesla would cut over and actively use the new hardware, turning off AP1.