When I lived in Michigan, my new company car (Pontiac Bonneville) had a front license plate "holder" (made of plastic) that was loose in the trunk
Since Pontiac has been dead since 2009, and the Bonneville died in 2005, that's a long time ago. They (the car companies) generally don't deliver what isn't needed. We had, over the time we lived in Michigan (33 years) about 35-40 company lease cars. None came with the front plate assembly since they were not required. Neither have any of the new cars we've leased since my wife retired from Ford. Who knows--maybe they actually did put these in the cars. I bet if the cars came with them, either the dealer or the company lease car facility removed them.
...which brings up an interesting anecdote about dealers removing things. A few years ago when the new S-Class was introduced, MBUSA lent one to the MBCA for display at Concours of America. We had it on display at our tent on the show field. When the weekend was done, we discovered that some "guest" at the show had pilfered the ash tray! We were so embarrassed at the situation. The company that managed their press fleet then told us how to "sanitize" the car for public display--basically removing EVERYTHING in the car that isn't bolted down (manuals, ashtrays, lighters, tools, etc.) and re-install upon return. Later I was relating this story to my salesman friend at Mercedes-Benz of Novi, noting there was an S-Class ashtray on his desk holding spare change. He was laughing, turned around, opened up a drawer, and in the drawer was about 25 new ashtrays.
"Nobody wants these &^%$ things in their cars any longer. So we take them out."