WOW. Good post an such a "simple" , overlooked automotive item.
I will say this about stainless steel rust-proof screws that not all stainless is "rust-proof" or corrosion-proof. MOST OTC stainless at hardware stores comes from "offshore" (China or Taiwan) manufacturers and is 410-series that is cheaper to buy and machine. The "better" grade is 302/304. The REALLY good grade is 316 (think surgical-medical grade or salt-water corrosion resistant), but that is like 6 times the cost of 410 series. 410-stainless is still better than plain steel screws that will rust. One way to tell if it really cheap stainless steel is to bring a magnet with you and see it the stainless steel is slightly magnetic. If it is, it`s cheap stainless. Works well on testing less-expensive (AKA, cheap) imported "stainless steel" kitchen knives/cutlery.
Laugh as you will, I put anti-seize compound on license plate screws, only to realize that MOST domestic car manufactures have PLASTIC threaded inserts in the sheet metal to attach license plate with.
Stolen license plates a big thing. I do not know of any dealer that substitutes the OEM screws with tamper-proof Torx head screws, the screw head that has a 5-sides star-shape with a "post" in the middle of the star drive to prevent removal or "tampering. Yes, they make special tools that "fit" this screw-drive, and yes, they are readily available to the general public, but most license plate thieves would not think of carrying these "special" tools around. Just food for thought.
(Only a CADD Technician who has experience with screws, the material types that they are made of, and the drive head on them would think of those things.)
Speaking of screw head drives, the screw cross on Japanese cars is different than a Phillips-head screw cross and is referred to as JIS (Japanese Industrial Standard) screw. Yes, they make special screw driver tips to "fit" these screw cross drives. Those of you who may have inadvertently tried a Phillips-tipped screw drive in a JIS screw, which seems to fit , but then stripped out the head drive when trying remove it to tighten it, well, now you know why.
More food for thought.....