I have just started to consider some carbon fibre parts for my Marcos Mantula. The car needs various parts before it's finished. One of those was to be a steel roll-over bar. However, my recent discovery of the possibilities of carbon fibre composites got me thinking. Is it possible for an enthusiastic amateur to build a lightweight integrated crash structure that was genuinely capable of helping with protection? What I'm thinking of is a structure that was not obvious once the interior had been trimmed. When working with steel roll-over structures there is plenty of prior knowledge as to what works and what would fail. Can this be true with Carbon fibre composites, or is this a black art known only to a few? How would I learn?