Model S and Model X share the same Vehicle Assembly Line. This is a conveyor-based line where workers assemble the cars starting with the Painted "Body in white". One way to minimize production disruptions/slowdowns while ramping up MX on the line is as follows: During a normal production day, there are two shifts on the assembly line. Model X assembly can be scheduled near the end of the second shift (once all the Model S's have been safely produced for the day). At this point if there are issues with certain assembly stations or intermittent problems they can be addressed and resolved. This is one example. I'm sure Tesla production gurus have lots methods to mitigate production slow downs. Q4 is a big ramp in volume and MX introduction complicates matters. Happy to hear other opinions.