A sticker is worse than tar or gum since the adhesives have cured and baked in the sun. Always remove any tar or gum as soon as possible! Dealers use 2 kind of badges: a straight sticker or a 3-d badge. If it's a badge, use a heat gun to soften the adhesive and then use a fishing line to cut the badge off at the adhesive. If the sticker is on glass, just clean the area and scrape it off with a new, sharp razor. A razor will damage paint so here is how I remove stickers.
You could buy special adhesive remover buffers but using auto paint specific polish and clay will not cause microscratches and even polishes the paint in the process of sticker removal. Don't use any kind of scotch brite or scrubby pad since this will cause major scratches to the paint. I've found that WD-40 or Goo Gone can remove some adhesives but this is a much more gentle method for the paint. 3M also sells car specific adhesive remover spray.
medium auto detailing clay
polish/light machine rubbing compound
microfiber polishing cloth
mothers powerball mini
First clean the area around the sticker thoroughly. The sticker might
have bits of sand stuck to the edges, make sure it's clean or else it will
causes scratches later. Peel off as much of the sticker as you can.
Clean it again.
Use the clay to pull off the adhesive. Clay is normally used with lubricant but depending on how thick the sticker is, you may want to use it dry to get the adhesive to stick to the clay and be pulled off. Experiment with and without clay lubricant to see which works best in your case.
I used some goo gone for auto paint to help soften the adhesive. The car specific 3M product is also shown above.
Follow up with polish. A mother's powerball mini with medium polish or light rubbing compound for machine use will pull off any clay/adhesive and polish the paint. You could do it by hand but the powerball mini is 100x faster. The powerball mini is on the harsher side for paint but is great for spot use. You can also use it for polishing headlights and taillights with plastix polish so it's a good investment. Do not use red turtle wax rubbing compound (in the white plastic can) since harsh rubbing compounds which are meant to be applied by hand will cause scratches. A light rubbing compound for machine use is lighter and will pull off the adhesive without causing scratches.
Final results - no scratches or evidence of the sticker. Depending on how long the sticker was there, you might notice a faint outline in the right angle/light due to aging of the exposed paint vs. the aging of the covered paint. It was hard to get the camera to focus on the paint so I put a piece of tape below the repair - no trick photography or lighting tricks here. Follow up with wash and wax.
It was hard to show the shine without the right light so here is a different angle. The hazy area is dried polish.
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