Got a new one for ya fellas...

How can I take off the warning stickers off the sunvisors? I tried a hair gun and it didn't work.

hmmm i'm not sure. i took mine off no problem. they just peeled off like a sticker...

since you used the hairdryer.. the glue has melted onto the sunvisor, making it very sticky. I would a lot of time a patience is your key now, that or maybe a small dash of goo-gone.