check out protectionandperformance in the uk. They have some cool designs and photos for ideas. Be kind of hard to take the roof off so for me Im fabbing/designing an internal cage. Too hot in Florida! Gordo.
PS: If you are designing your own Id recommend saying this site to your favorites. You dont want to cut corners with safety. Gordo
http://www.alrc.co.uk/new%20regulations/rbindex.htm