another vote from me for goop!
what i usually do for something like a visor is to tack it into place with hot glue so that it doesn't move around on me, then goop in around the hot glue.
once the goop is set, you can either pry out the hot glue (though the laws of hot glue apply - it will never hold when you need it to, but won't ever come out when you want it to.) or just leave the hot glue.