Integral? Maybe not, but why would they let it wither? BMW makes 2 series, 3 series, 5, 7 series, X series etc. You wouldn't see BMW letting the 7 series die in favor of the 3 series. It's a different market, some want the bigger car, some want the extra luxury, some just want a more exclusive vehicle.I actually agree with much of this. I don't view the S/X as integral to Tesla's future success as you seem to, but I agree that, in their current form, you need very particular reasons to choose an S/X over a 3. Once the Y is out, those reasons narrow even further(the main one being storage/passenger capacity).