I have worked in body shops 20 years, and owned one 17 years. I have unfortunately removed a lot of adhesive. My best luck was always wax and grease remover, like PPG DX330. I used the corner of a clean rag, soaked dripping wet, applied to an edge= a starting point. I always started at one end or another, never in the middle.
Let the wax/grease remover remain wet, dab it with a rag, brush it, whatever you want. It will not hurt any painted surface! Let it soak for a minute and try to scrap off at an angle with a hard Teflon type scraper. You may have to work on the soak time to figure out when to scrape it off. You might have to apply DX330 2 times before scraping off the adhesive, maybe not. You probably will have to come back and do a second pass to clean up what you did not get the first time. Don't kill yourself trying to get it all removed perfect the first time. Come back the second time with a clean rag, and its easier to do the final clean up vs. using the same nasty rag that has the bulk of the adhesive on it. The wax/grease remover should not soften the paint enough that you scratch it, as long as its OEM paint. If it has been repainted, all bets are OFF!
If you only had a small spot, you could try finger nail polish remover. It works, but its pretty weak.