Since I am in automotive, and see a lot of vehicles on a daily basis, not 100% but very high in my observation, conservatives put their bumper stickers on the bumper , liberals paste them on the vehicle anywhere, where it can damage the paint to remove them without solvent. If you watch the video again, I think you will see what I'm talking about.
People like me, don't put any stickers on the vehicle, my sticker is not going to influence anybody, instead, I go to yard sign parties, fund raisers and phone banks to get my point across and my candidate elected.