Cockpit Intrusion Per D.6 of GCR

Can anyone tell me how the subject rule is satisfied in FC cars?
D.6.c.1 states " Panel(s) min of either 0.60" heat treated aluminum (6061-T6 or equal) or 18 guage steel, attached to outside of frame tubes". I read it this is required for anything made after 1986.


Some cars, such as the Swift, have no aluminum panels between the front and rear roll hoop bulkheads. Because of the way the bodywork is contoured around one of the tubes, it does not appear possible to attach to outside of those tubes.


Perhaps it is satisfied by D.6.c.2 via kevlar body reinforcement?

Kevlar is how most meet the rule.