First of all you cant use expanding foam and fiberglass resin together. The resin will chemically react with the foam and melt it.

Also when working with fiberglass in your interior tape off everything, fiberglass resin will not come out of carpet, seats, or any cloting you are wearing.

The mixture of the fiberglass resin to hardener is very important, I suggest you practice alot. Mix too much hardener and the fiberglass will cure before you finish laying it, or get clumped if you continue trying. Mix too little and it will not cure properly and just run like gel. Mix it too hot and it will warp the mold from the heat of the resin reacting.

As far as making kick panels go, it involves making a fiberglass mold of the floor. Then a wood plate or baffle for the speakers. Angle the speakers appropriately and secure the plate to the mold to keep the angle. Remove from vehicle, and stretch cloth over the entire front of the kick panel including the panel and glass over it. Touch up with bondo, and more glass if you need to increase strength.

Good luck.