A lot of interest in the clam hinges. They're easy to make, but there are a few hurdles, it's a lot more work than it appears and is probably why no one (like Sector111) has offered them:
Battery must be moved - I moved my battery (Odyssey PC680) into the cabin, behind the passenger seat on the accessory shelf. The existing battery cables are relocated, the length is perfect! And the cables route nicely behind the rear plastic cover. A bonus is the battery weight is moved forward and offsets some driver weight.
Wheel Well Liners - Must be attached to either the clam or frame, but not both. So, there are additional supports & brackets I had to design.
Rear Diffuser - I had to build an aluminum frame to support the diffuser. My muffler area is open, the OEM metal grate is removed. So, my diffuser is supported entirely by the car's frame, it is no longer attached to the rear clam.
Roll Bar Cover - Requires cutting
. Yup, cutting of the fiberglass body work. Not many people are willing to do this. Additionally, holes are drilled down into the cabin to make way for quick release pins that secure the rollbar cover/clam. The qr pins are released from within the cabin area.
Engine Lid Cover - The two hinges on the engine lid are bolted through the rear clam and into the lower body work. A slight rework/reinforcement is required here.
Top/Center Brake Light - wiring must be lengthened and rerouted.
Lower Body Work - Reinforcement and cutting is required to compensate for the bolts removed that fasten the upper portion of the rear clam to the lower panels below the side scoops. Some of the trim has to be cut into two pieces - namely the long black trim piece that outlines the side scoops.
You can see that the hinges are a small part of hinging the rear clam. My rear clam is very solid, no vibration or cracking - as solid as OEM. It takes around 10 seconds to swing the clam open which is great for engine work. < 2 minutes to completely remove the clam - pull 4 pins and one electrical connection (rear brake/directionals) and remove!
I don't have CAD drawings of the hinges - I cut them from 3/8" aluminum plate using a hacksaw and a LOT of patience.