Fiberglassing to Plastic

Hello.

I know this topic has been covered a lot.  Please hear me out since I have read every thread that I could find on the subject.  It seems like the only real viable solution to the problem of fiberglassing over plastic is to drill many small holes in the panel, etc etc.

Here's what I'm doing.  I would like to install 6" Focal speakers in the lower sections of my doors where the map basket is (as close to the hinges as possible).  Here's a picture of my door to give you an idea:

The speakers are quite a bit deeper than the map basket, so I need to build it out a bit.  I also want it to have a factory look.  In other words, just gluing the rings in place with dowels and stretching fleece over it isn't what I want to do.  I want to use a combination of hardboard and fiberglass to keep the thing has angular-looking as possible.  But I want to use the factory mounting locations of that map pocket.

So what I want to do is cut out that panel so that only the edges are left.  Then I want to use the dowel method to attach the pieces of hardboard what will be cut to the proper shape and size.  The hardboard will replace the section that I cut out of the plastic panel, but the dowels will hold the hardboard a few inches farther away from the door that the orginal panel was (i.e. the panel will be deeper).  So obviously there will be gaps between the hardboard and the remaining plastic pieces of the OEM panel.  The wood will then be connected to the remaining factory plastic panel via fleece and fiberglass.  So now that I've described my plans, here's the question (sorry, that took me a while, but I want to be clear about what I'm planning):

Since fiberglass resin likes fleece, and fleece can be glued to plastic, couldn't I just use some adhesive to glue fleece material to the plastic and then use the same old fiberglass application process?  In other words, the fleece would be the "middle man" between the plastic and the fiberglass.  Will this work?  If not, please propose other solutions!  I've never done fiberglass, but I'm a quick learner and I've done TONS of research on the subject.

Thanks guys!

Peter

Okay, I re-read what I wrote and I just want to make it crystal clear what I'm talking about.  It's hard to describe without drawings, so here's my classy attempt in Paint.  The red stuff is what I will build out of wood.  The gaps will be covered via the fleece thing.  Okay, I'm done talking.

Thanks for your reply!  I'm not sure I followed all of that.  I'm going to try and repeat the steps in order.  Tell me if I have it right:

1) Drill small holes in the plastic

2) Tape the backside of the panel so that the resin will accumulate and harden (i.e. so that it won't drip through and so that it will pool up at the bottom of the hole forming "rivets")

3) Drip fiberglass resin into the holes to make sure they fill

4) Apply layup adhesive to the outside of the plastic panel

5) Stretch the fleece over the plastic (where the layup adhesive is)

6) Saturate the crap out of the fleece with resin so that it "connects" and adheres to the resin in the holes

7) carry on with regular FG layup procedures.

Is that how it goes?  Do you have an example of a layup adhesive?

Thanks!

Thanks a lot guys.  I'm assuming cabasil is the layup adhesive, right?  And what is an example of a thickening agent?  Sorry for all of the questions, but this chemistry/chemical stuff really throws me off!

Great, thanks.  I only have one more question...  What is a layup adhesive or some other example of a glue that won't lose it's adhesion properties when it comes in contact with FG resin?