Decal eraser
If you're referring to the visor on the roof(exterior)you can try mayonnaise.Let it sit for 5-10 minutes then use a soft scrub bristled type brush used for scrubbing tires or a razor blade.Be very careful to not dig into the paint,keep the blade flat.If this doesn't work,an sos pad or never dull should do the trick.Don't scrub too hard when using these pads.Mayonnaise is really great at removing bugs and tar so adhesive residue from visor should be no problem
Goo-gone, charcoal lighter fluid, paint thinner, gas, etc.
