I asked samething a year ago and the best thing ever is to peel the sticker off and use wd-40 to remove the glue super easy and fast ! it don't ruin anything and u can use it on anything and it leaves it clean when done !
I've used both, both is good. Gas dries out real quick and is a little quicker getting heavy glue off, and no it's never dulled any color plastic. If you use WD 40 you have to get that back off before you sticker it again or it won't stick that's why I have my preference .
Heat gun on low for 5-10 seconds, start the peel off of the sticker and go slow. Use heat gun very briefly if it cools off and doesn't come off as easily. When done use 3m adhesive remover. Won't harm plastic or paint and you can get it at any O'rileys, pets boy or similar store. Spray it on the goie, wait 10-15 seconds and wipe off with a paper towel or shop rag. Reapply as needed for thicker reside.
i peel the sticker and use PREP-ALL u can get it a your local auto paint supply company, it won't harm the plastic and it takes the glue right off, use it for cleaning all surfaces. good stuff to keep around for all types of things.