Re: PVC Rollcage - I think people underestimate the viability of polymers as a safety-structure material. While PVC may not be the best-suited polymer for the task (it's a bit hard & brittle), there are others that could do quite well - maybe even better than steel, since many polymers tend to deform elastically to failure, whereas steel experiences significant plastic deformation, allowing the driver to be pinned into place. Just my 0.02