Why is raising the striker plate slightly to raise the rear of the door a fraction of a millimeter a bad idea? (Tesla did that on three of my doors to raise the rear, just a fraction of a mm.) In my mind it would be easily within the tolerance of the hinges and just add a tiny amount of the play at the hinges. (It would actually unload the hinges slightly, which should arguably be good for them, i.e., the striker supports more of the load of the door, taking some off the hinges.)
Elon said the multi-coat red is the hardest to apply. I'm not a painter, but If you look at the multi-coat red closely, there appear to be possibly 3 coats above the base color coat and below the clear coat. One with a gold flakes, possibly a separate one with silver flakes, but a definite coat above that which has no flakes or opaque pigment but is a translucent red, sort of like a dark red clear coat, above the other layers but below the regular clear coat. Getting all that right probably is harder or takes more steps/time in the paint booths and likely results in a higher costs and a rejection rate.
So yes, it probably does literally cost more to do due to the additional time in the painting process and higher probability of rejects.
The pearl white seems a similar concept, but maybe without the top translucent color (red) coat.
(I have no inside information about how this is done; it's some guesses based on observations.)