Use a de-greaser like WD-40,give it a good spray,leave it for 45 minutes then go at it,and the glue should have softened and be more easier to scrape off.I use this method everytime i take graphics off frames/parts i'm prepping for paint.Nice truck by the way spoiled goods,my brother has a Toyota Hi-lux crew cab pick up,lovely machines.His is a lot smaller than these American models that you own.
All the best to you and yours for the new year m8.
Gary.

 Goo Gone and a thin razor blade works too - then use an alcohol and water solution in a spray bottle to get it squeaky clean if you plan on applying something new. It's what we do for full car wraps and decals.

 "My bike takes me places school never could"

 YOTA!

 i call YOTA to my dog,