Fiberglass Sub Enclosure

The box im building is kind of complicated, so it would be a huge pain if not impossible to lay down my layers of fleece seperatly and staple them to the precisley to the MDF were its routed out with a rabbiting bit, I was wondering if I could just staple down three layers dry and then soak with the resin? Also should the three layers of fleece with resin be strong enough  for the application? I want to make sure that when im done fiberglassing and using body filler that the sides are level with the rest of the box, casue im covering the actual box with vinyl, and the front containing the speaker rings will be painted. And Last question, Does The fiberglass have to be sanded before you apply the body filler?

What you want to do is only use one layer of fleece and about 6 - 9 layers of matting and resin. Using soaked fleece will not give you a solid enclosure, nor will it give you a good sounding enclosure. For proper bonding of body filler, you have to rough up the surface of the fiberglass with sand paper.