I would only use acetone (or lacquer thinner or MEK) as a last resort. All those will damage the fiberglass quite quickly unless extreme care is taken. But fiberglass is just about impervious to everything else, including mineral spirits. Goo Gone is my first choice for any adhesive residue, though. Then Goof Off. Some sticky stuff, e.g. pine pitch, requires an alcohol to dissolve it, so try some isopropyl alcohol (any drugstore has it) if the usual thing s aren't working.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL