Excellent idea. A thin foam panel several inches wider than the center ceiling would also help with heads hitting the center ceiling when sitting in the center seat.
Examining the area carefully, I am impressed that Tesla Motors designed the "Model X" trim plate with a slant at the top that helps anyone who grabs the area to have fingers slide off and down.
It is disconcerting when looking at the beautiful Model X trim around the opening for the falcon wing door and see fingerprints from my riders. That means they had their fingers on the location where a pinch or crush could take place. I totally understand the concern of the OP.
One help would be a sensor to warn if fingers are on the trim. Think about a house lamp where the user touches the metal of the lamp to turn it on and off. Imagine the plastic trim around the falcon wing opening having a touch plate that sounds a chime when being touched. While that would help, it wouldn't stop a last second attempt to push fingers into the crush zone. Another option would be a light beam, like a garage door opener has.
What is interesting is the lack of visual queues about the hazard. The attractive trim that shows "Model X" doesn't look threatening. There are many labels that could assist those who have a need to know. This one is wide and features two visual queues.
View attachment 111603
Pinch Point Hazard Keep Hands Clear ANSI Warning Label, SKU: LB-2430
While not pretty, IMHO, I would suggest the use of this label for UBER Model X drivers to warn your paying passengers.