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To ensure the chair is still structurally sounds it will require intelligently placed support members. I recommend taking all three of the chairs shown in the photos as reference for how to support a chair in a clever way while minimizing weight and space.
This is what Eindhoven did in their 2017 car, more photos can be found here https://photos.app.goo.gl/jwR6BREPAebiQEGe8
Goal
Design and manufacture lightweight and comfortable seats that impress whoever sits in the car while minimizing space used
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