I appreciate all the input and advice because this is the first liner I'm building. Mine is similar to the Maro Special chassis in most areas. A Carbon/AluminiumHoneycomb tub will install from the bottom and be bolted and bonded to the chassis via 18 locators. I've designed the tub already but I'll only assemble it once the chassis is completed. I'm a small guy (5'7") and weigh around 150lbs. so the tub is a box within a box and when finished will have the wiring and other components running through it from the motor through glands built into it. I still have the seat from my F2 car that was custom made in that monocoque so I've based the driver's cell on those dimensions. It's a tight fit with no wiggle room. I built a Carbon head support for side to side movement that is similar to the NASCAR ones and based on my Simpson helmet there is very little gap (1/4"). It is the strongest, stiffest component I've ever made. 14 layers of the black stuff over a high density core material. I've already welded in the mounts on the roll cage but will only bond in the locators on the support once I've had a chance to sit in the car suited up and strapped in. My only concern is that in a roll over ones legs tend to come off the floor and as someone missing a Patella or two and having a steel pin in my left leg I kinda want to protect the legs. Any ideas on leg protection above the knees?.
I was going to fabricate a Butterfly style steering from metal but I have so much Carbon fabric here I decided to go the composite route. It too is super strong but the cool thing is that it's formed to the shape of my hands. No I never duct taped my hands to it a went to sleep with it while the resin cured.
. The Canadians had me pee in my new skates and sleep with those strapped on. Only did it once. The wheel isn't quite finished yet but here's a pic of what it looks like without the centre cover.