Yeah, having the right tools will definetly help you out
Unfortunately I do not have a template. My orginal plan was to use the cardboard as my template, but I soon found out that it was too flimsy when I started laying the fiberglass, so I decided to just lay the fiberglass over the cardboard instead.
If I were to do it over again, I would most likely use plywood or a thin type of wood for the mold, so that it would be stable enough to hold its shape for the fiberglass. It would also be much lighter as well.

I guess you can go with aluminum as long as you have a bending machine or a welder to put it together or you're be paying someone to do it for you, unless you have a hookup. It also may be a little heavy depending on how big it is .... maybe junky can chime in with the aluminum stuff since he's done it for his car.

 

Yeah I will say that 1/8" aluminum is light and can be worked/ bent if you have the right tools, I did not so I had to sub out some of those pieces and it gets expensive quick, better to do it all yourself if you can. Rivets actually work very well for attaching fins etc and are hidden/flush and light vs bolts or getting into welding which would be a whole other deal, but if you can weld aluminum yourself then great, it will ad more weight then a few rivets though. Once I put all the individual pieces together and mounted to make sure fitment was exactly where I wanted it, I removed and took to get black powder coated and re installed. I’ve had it on the car for about a year now, I’ve been quite happy with the mounting and powder coat. Everything has been trouble free and held up nice.

I'm currently in the beginning design faze of additional diffuser pieces to fit behind the rear wheel openings. As of now my diffuser just covers the main trunk area between the pipes.

 

Looking to do a few more projects as well, but it's gonna have to wait til summer, just to flippin cold right now.

 

Yeah I hear that, I’ve got a one car garage that doesn’t give you enough room to open a door let alone use it to work on anything, the weather is an added element for sure, but I cant help but feel creative during these months of being more indoors, and since I cant get out and really enjoy the car like in the summer I might as well work on it.