From a consumer point of view, I believe the following changes went into the Model X since late 2017. I located the following
#1 MCU2
#2 The stamping under FWD is a little different to avoid for scratches
#3 The rear cargo tray has a much nicer pull and it is thicker
#4 I believe the FWD button might be different color than before
#5 The bezel around the center screen
#6 Interior color combo
#7 Under the frunk, the cut tag is gone. They also changed some of the plastic pieces.
#8 Some small plastic body parts change
#9 The door latches seem quieter, but not 100% sure
#10 The FWD seems to close slower
There are probably more, but these are the obvious ones to me.
#1 MCU2
#2 The stamping under FWD is a little different to avoid for scratches
#3 The rear cargo tray has a much nicer pull and it is thicker
#4 I believe the FWD button might be different color than before
#5 The bezel around the center screen
#6 Interior color combo
#7 Under the frunk, the cut tag is gone. They also changed some of the plastic pieces.
#8 Some small plastic body parts change
#9 The door latches seem quieter, but not 100% sure
#10 The FWD seems to close slower
There are probably more, but these are the obvious ones to me.