The stupid short time allowed for edit did not permit the pics that went with my last postWhen you are at a track, check what other people have done with their tanks, I would be surprised if you cant strike up a conversation with some smart people who could have some spare material, offcuts of Nomex, Kevlar, honeycomb aluminium etc. I have scavenged heaps of free carbon fibre and even titanium over the years, you don't know until you ask and most people in racing are happy to help on projects such as yours.
Version 2 may be easier to achieve than you think.
Many big teams upgrade heaps of stuff in the off season and you would be astonished at what goes in the skip bin.