Have one The Mountain Project - "Die with Memories, not dreams" sticker on my 60 series land cruiser, nothing on my "work" truck. The same cannot be said for all my coolers and garage storage. That's where all the stickers go.
But, I've been thinking about something similar to this lately. This granted that I have never had any negative interactions in the field, but listening to everybody whine about non-residents on this forum...
To avoid the Non-resident hate for driving a vehicle with Texas plates all over creation, I've been contemplating stocking up on random state university/alumni stickers and putting one on the truck when I'm out of state. Think hunting public in Oklahoma so throwing on a Tulsa or Oklahoma Panhandle State University sticker. Don't want to get too hard on the in state rivalries (OSU/OU, etc). Or a Wyoming cowboy sticker, Montana State, etc depending on where I'm hunting at any given time. Then worst case guys see it and think to themselves, "Oh, its a local who moved to TX for work and he came back to hunt."
Come to think of it, removable magnets would be better and just throw them on the tailgate. Keep a little folder of them under the back seat.