looks like a good write up. i usually use painters tape and make a mold of the location that im going to make it, for huge setups like that, using MDF will work, but if you're looking for like the stealthbox idea, use painters tape or aluminum foil to mask the area thats going to be the bottom of your box, like this :https://www.facebook.com/photo.php?fbid=150244648382187&set=pu.115635381843114&type=1&theater
then you will add 3-5 layers of resin and matting to the tape. before putting the resin/fiberglass down, make sure to put something like vaseline(thats what i use cuz its cheap) or wax or something. when the fiberglass cures, without something like that its gonna be a ***** to get it off. then you make a ring out of MDF which is what will mount your speaker in the box. i dont have a pic of that cuz i forgot to take one. but you'll have something like this:https://www.facebook.com/photo.php?fbid=115641668509152&set=pu.115635381843114&type=1&theater
basically you see inside the box what looks like stilts? thats what you do. you take the ring and mount it in open air with the stilts to the bottom of the piece you just made, with staples or screws. then you take the fleece, and wrap it from the ring down to the underside of the mold of the trunk you made(painters tape) use spray adhesive to stick the fleece, its much easier. make sure there are NO wrinkles or sags in the fleece. these will make life difficult later when its time to paint. you then do the same thing, adding resin and fiberglass. you see here where the painters tape was before is now the boxes?https://www.facebook.com/photo.php?fbid=150244755048843&set=pu.115635381843114&type=1&theater
thats what i mean by making the molds in the beginning. all the MDF boxes and bar are there to create a "frame" like they said in the other DIY to lay your fleece. this instance i made a set of boxes to house my subs, and items to hold the amps and caps, and stretched fleece from them to the sides of the car, and fiberglassed it, which created this:https://www.facebook.com/photo.php?fbid=150247545048564&set=pu.115635381843114&type=1&theater
i did it this way instead of how they said in that other DIY for two reasons. 1) it makes it so that the facade is removable so i can tune the amps and everything without dealing with the whole big piece, and 2) its a hatchback, didnt really have any other option. when the fiberglass cured i just cut around the edge of the car and pulled the whole facade out. you can see here:https://www.facebook.com/photo.php?fbid=150244925048826&set=pu.115635381843114&type=1&theater
where the facade and the other boxes are separate. in my case i was trying to save weight, and MDF is heavy. so thats pretty much the nuts and bolts of it. make sure to have A LOT of gloves, brushes, lacquer thinner both to clean the brushes and any spills, and a lot of patience. when you first start mixing the resin and hardener, you will most likely lose some due to it hardening before you use it up, happens all the time. for every 8-10 oz of resin you need like 4 drops of hardener. as you get used to it and the temp of the day and sun, you'll figger out the right ratio. its not THAT complicated really, just takes time and practice. if you have any questions feel free to ask and i'll help you out.