My one friend and I have been leaving odd gifts on my friend's car with notes like "I think this fell out of your car" nothing of value. Nothing that can damage the vehicle.
They do make little 1-serving packets of PB, kind of like the ones for BBQ sauce or honey mustard. Sometimes you can find them at hotel continental breakfasts.
https://www.allrecipes.com/article/what-is-a-continental-breakfast/
A very tacky car freshener. Some are dirt cheap, the cardboard ones I'm talking about. Pick a design that is silly or ugly for them... Or maybe a fragrance that you know they're not a fan of
"I think you dropped this" and its just a big dollop of Vaseline right on the handle
Rubber chicken. Though don't do that to Jair Bolsonaro car, then it would be NSFW object.
A cracked egg, or the lid of the pack of sugar you put in their gas tank. A weapon that was used in a murder. I guess it just depends how much you hate them
Snack bar wrappers. Really weird ones that only really little kids love.
Underwear, either gender. Though you said no value, so uh, dryer lint? Clothes pins? Dog biscuits? A dog poop bag with pudding in it?
