Since the car is so new, you only needed to park it in the sun and use the dental floss... the heat gun might have caused problems.
Since my car is so old, i used some of that "sticker remover" and it worked great. Combined it with some goo gone for the left over stuff, and used an adobe to scrape it off. Cant even tell!
But, my pinstripe did what you are talking about, and its cause the pinstripe was so freakin old and corroded... Wierd.