Trying to get this stuff off my tailgate

So I got a 98 Dodge Ram back in February and I named him Purdy Face. I decided to remove the black plastic on the tailgate because I think these trucks look much better without it. I heated the plastic with a hairdryer and that made pulling it off a breeze. Unfortunately, most of the glue or whatever is still stuck on the tailgate. I used goo gone and the hairdryer again, but there's still a lot on there. If anyone has any suggestions that would be great! Here's a few pics of Purdy Face and his ugly tailgate!

 

Nice find ... single cab and long bed!

 

Try wd40

 

you powerwash it yet? I'd go to a car detailing website & see what there using & try it. If not you'll have to call a detailing/body shop & get some advice. See what chemicals might be stronger yet safe

 

Goo Gone and a plastic razor blade
Or one of them adhesive removal/eraser wheels you stick in a drill....

 

This here thread might give you some ideas

https://www.tacomaworld.com/threads/cant-get-this-sticker-off.258047/#post-6273483

 

This. Let it soak and give it a little elbow grease.

 

Thanks for all you're suggestions! I tried the eraser wheel and it helped a little, but it kept falling off the dang drill! I'm not worried about it right now cuz the truck's covered up for the winter. My main problem right now is my 2000 Ford Ranger I recently bought to be a winter beater. According to my dad, the rear end is leaking and the shocks are rusted off, but it's fun to drive!