Periodically I will see someone with a "III% er" decal on their truck. I had no idea what that was so I did some checking. I'm not saying I'm completely on board with what the 3 percenters represent, but because of that decal I at least am now aware of them.
Personally, I feel the GOA (gunowners.org) is far more helpful on 2A issues than the NRA yet many people don't seem to be familiar with the GOA. I would imagine me having a GOA sticker on the vehicle would at least expose one or two people (maybe many more?) to this organization.
The SAF is likewise under-appreciated, in my estimation.