Could try a heat gun, and for the glue I would try "goo gone" I think is the name

 

Planning to take mine off. Seems like the consensus is to use a handheld steamer. Heat gun and goo-gone was 2nd place.

 

Use a heat gun on low settings and whenever you peal stickers off, it is best to pull back as you lift up. So when I mean pull back, it is a pulling towards you action and not just pealing back

 

Also wait for a warm day. Let your car sit in the sun a bit, makes it a bit easier

 

3m makes a decal remover that goes into a drill. If you plan to re wrap is then it should be fine. Everyone recommended it for my trailer, but the paint was so thin n that it smeared it. But it's made for automobiles

 

Prep-All Wax and Grease Remover by Kleen Strip works well for softening and removing the glue. Not sure if it will affect the plastics tho, only used it on automotive paint.

 

I use steam, works really well and very clean.