If the heat method doesn't work, go to the auto body paint supply store in your area. They have a tool made for a drill that's about $10-20 which is basically like a big eraser on a stick. Spin it slowly and it erases decals without damaging paint….Like this….
http://paceperformance.com/i-7137057-ewt37023-vinyl-eraser-and-arbor.htmlYou can also use this tool to remove glue residue left over after anything glued on was removed.
Mark Davis
Palm Beach Gardens, FL
amateur photographer, hot rodder, motorcyclist, adventurer
"Four wheels move the body. Two wheels move the soul."