Lost it at the car wash
No one took mine, but I got the vehicle washed at the local car wash, and it was missing after that. I went back and asked about it, and was told that hitch plugs are always coming off in the wash. They had a whole box of them. Of course, mine wasn't in there, but another one was, which said TOYOTA on it and had the logo. It was pretty new and fit my hitch just fine, so I took it.