If the adhesive is yellowish brown, it may be a polyurethane sealant, since they tend to turn brown when exposed to UV.
I am trying to remove an unknown adhesive from where it was used to bed dead lights, a job track and chain plates. There is some silicon there, but also a yellowish brown adhesive. 3M didn't mention whether it is safe for fiberglass.Specially blended solvent which provides easy cleanup of most types of adhesives, bugs, greases and oils, overspray, silicone, waxes and tars.
Will not harm most thoroughly cured automotive paint, vinyl or fabrics when properly used. Part numbers 08984 and 08986 have a VOC content of 816 grams per liter (6.8 lbs per gallon). Composite Partial Pressure equals 4.81 mmHg. Local air quality regulations may regulate or prohibit the use of surface preparation and cleanup materials based on VOC content. Consult your local air quality regulations.