Dental floss works well if the adhesive is gummy but the floss may break often too. I've used the string, or whatever you call it, that they tie up balloons with too. It's stronger than the floss and didn't scratch.
I used a product called Goo Gone on my truck that seemed to work really well without damaging my paint. I used it to remove my old sunroof wind deflector as well as some fishing line and it came off fairly easily.
3M adhesive remover will work but you need to be careful and use minimal rubbing as it can dull the paint (clear coat actually) but if you do get carried away it can be buffed back to a shine but the 3M stuff will work.