If they do it after you pay for the car, sure. Before you give them any money, it’s their car to do as they see fit.
That’s for me, the buyer to decide. A pickup truck is also the incorrect product for me, because I don’t want one. Someone else may not want a black car. We don’t want stickers or badging on our cars. Others may want a black pickup truck and doesn’t really care if it has a sticker on the back for whatever reason. All that is totally fine - it’s our choice to buy something or not.
But it’s certainly not vandalism for the dealer to do that to their own car any more than it is for me to put an “I love puppies” bumper sticker on my car and then sell it a week later.
I would’ve thought they install licence plate frames when they put the cars out on display, though I do find the idea of dealerships running around randomly mounting them to other people’s cars amusing.
Yes. They own the vehicle.
You are free to do whatever you want when you finish the transaction. Which typically is actually a few days later after the bank clears it. Or you can ask for them to take it off. Dealerships just let it go early because they rarely run into issues closing the finance. And NOBODY ever brings their own plate holder. But yeah, “vandalism” 🙄
Imagine buying a painting and they srpay paint a red X on it before handing it to you.