Just watched the Youtube video below discussing 8 more possible Model 3 Highland upgrades in addition to the 6 we already know about:
Ambient RGB interior lighting
Ventilated seats
Rear infotainment screen
New headlights/taillights
Hardware 4
Drive by wire steering
The other 8 are:
Hatchback?
Longer nose (power Frunk?)
Suspension raised higher
Larger M3P battery (14% increased range)
Structural battery config (10% less mass, 370 less parts, more Manganese, longer life)
New drive unit w/no rare earth metals
Enhanced sound system
Front and Rear giga-castings
Here's the video: