The 2003 CAMS manual gives very detailed specifications for a roll cage. I will admit that I have not read them but apparently since the incident at Phillip Island recently all cages will require TIG welding. The MIG is just not good enough anymore.

The CAMS manual can be bought direct from CAMS for around $40.

If your still wondering by Christmas, I'll be constructing a cage for my own Coupe come track car - as lightweight as possible whilst still meeting CAMS regs, with the goal of spending $500 or less. (maybe someone will have to tell me I'm dreaming - but that is all that is in the budget for a cage at the mo')

If you find the specs feel free to post them, otherwise I'll try an article with photos towards or straight after Christmas.