ap1 George

Gasoline works. I had painters tape on my car from painting, it got soaked with water and baked in the sun and the tape adhesive wont come off. Gasoline and a paper towel will do. I wouldn't doubt it would also take off any existing external sealer or wax just make sure you wax or seal that area again

osoquik

Hot Summer Day + Goo Gone.

LDTFbsst

I just used a heat gun, heated it up a bit and it came right off. For the more stubborn crap it was a little bit of goo gone and my fingers. cleaned up really nice.

cosmomiller

Rather than gasoline, naphtha (lighter fluid, hand warmer fluid) does the job but evaporates quickly with no smell or residue.

Industrial adhesive remover is MEK or methyl ethyl ketone. I use it all the time. Not for sale in California this year. Bought a gallon before that happened. Also used to prep PVC/hypalon/vinyls for adhesive. (Think our convertible tops)