Velco does not stick to vinyl and it would not last long or hold fast either. Snaps as Hud suggests will work well. You can buy a snap tool to attach the shiny button parts
to the fabric
then dill, seal, and screw in the snaps to the fiberglass
. It's been done for years that way.
They are usually done on the out side of the cock pit close to the upper edge. That way water
drips outside and not inside. If need be to you can sew short straps to reach a snap location lower than the upper edge of the cock pit if it would make a nicer tighter fit. It is best if the panels
are taunt but not stretched. They are easier to see through and won't flog in high wind
They aslo make a snap tool that makes snapping them in place a whole lot easier and easier for removal
as well. Yanking a panel to unsnap it is not good. They are about $20 and are well worth it. I can not snap our dodger
in place without the tool.