Changes that I know have happened with my large group of friends, in order of occurrence:
1) Color Exterior
2) Color Interior and trim options and going to Dark Alcantara Headliner (really only 2 color choices now, tan or black seats as grey is delayed at present)
3) Removing Rear Facing Seats
4) Changing to/from Premium Sound
5) Adding Premium Interior Package which is tied with Wheel Size or Style Changes
6) Adding Climate, if you are in the North, you should get this, a no brainer
7) Going from Standard to NextGen seats (when that was once a choice)
8) Removing Air Suspension or Adding Air Suspension
9) Adding Rear Facing Seats
10) Adding / Removing Pano Roof (observation, those in the far north or south tend to remove due to cold or sun heat)
Oddly enough, none vacillated on AutoPilot, it seems you are in that camp or out of it. TACC is really worth it IMHO. Also you are either in the Dual Motor camp or not depending on your location. Observation, those who do not get Dual Motor also do not get Climate, Pano or Air Suspension... essentially a mildly optioned car.
Lastly, I know of 3 folks who wish they could click their heels and have the rear facing seats removed and their pockets lined.
My advice.... get the biggest battery you can afford, especially if you live in a climate that gets COLD in the winter. Hear this and try to understand it.
You can peruse the Order spreadsheets and get a sense what folks are ordering by region (north or south or central).