Yes but a bonnet or door isn't going to be the difference between you walking away from an accident or you never walking again. If your car seat breaks when you have an accident, suddenly all those forces are transferred to your spine. 

I can´t see why all this trouble with the seat. I´m aware that is a safety part but a door, an hardtop or even an Helmet!! are safety parts and i´ve seen those discussed.

For safety critical componants generally if you cant have it tested or lack the facilities/know how to do a proper structural design and strength calculations, then Generally we recommend you get someone to make it for you.

However, if you copy something similar that you know is safe (in terms of general layup etc) and over engineer it a bit then you should be ok - but it is still a risk you have to understand.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

http://www.youtube.com/watch?v=aF3ll_h9EAw

The video shows infusion of a seat, and what material is being used.
If I were to build one I'd probably include some 5-8mm aramid honeycomb just for good measure, with the honeycombs around the attachment points filled with flox and a few localized reinforcements from the leftover carbon.

Suggested layup schedule:
200 or 245g outer layer, 2*300g or so biaxial carbon, honeycomb, and the same on the other side for symmetry.

Should be plenty strong, but do your own research!!

Because without crash testing, you don't know if you've got something something decent. A lot of money and engineering goes into making a road worthy seat. 

I can´t see why. I see many people using  Ebay seats that everytime you seat it seems that is cracks a bit more. Most of the seats even those which are known brands are poor fiberglass and i´ve seen some of them cracking in simple daily use. So why not build something decent?

I generally encourage the creative process...except when your safety might be in jeopardy. Think about it man, your life could be on the line with this project. 

Hi all,