2006 Prius with gray metallic paint. Has some glue like substance on the metal hatch near the license plate and on the adjacent plastic bumper. No idea what it is or how long it's been there.
APC had no effect. Degreaser had no effect. Goo Gone had very little effect.
Any suggestions?

APC had no effect. Degreaser had no effect. Goo Gone had very little effect.
Any suggestions?