Thinking out loud and following the rules are two different things.
8. Safety a. An electrical master (“kill”) switch is required. See GCR Section 9.3 Master Switch. b. Installation of a fire extinguisher or fire system is required. See GCR 9.3 Fire System. c. Air bag systems shall be disarmed and may be removed. d. In any automobile where allowed removal of upholstery, seat belts, etc., creates an opening between the driver/passenger compartment and an exposed gas tank, or part thereof, including the filler tube, a metal bulkhead which completely fills such opening shall be installed. See GCR 9.3. Fuel Cell Specifications.
9.3.26. FUEL CELL SPECIFICATIONS All cars must be equipped with a safety fuel cell complying with these specifications, except for Touring, Spec Miata, Improved Touring, production-based Vintage cars, or as otherwise specified in the GCR. All safety fuel bladders shall be constructed and certified in accordance with the FIA FT-3 or higher (FT-3.5, FT5, etc.) or SFI 28.3 specifications. Fuel cells do not time out and have no expiration date. Alternatively, safety fuel cells shall be constructed in accordance with FIA FT-3 or higher or SFI 28.3 specifications and tested to those requirements by an independent facility as witnessed and certified by a Professional Engineer. The results of these tests shall be submitted to the Club Racing department for inclusion on a list of approved suppliers. All safety fuel cells shall consist of a foam-filled fuel bladder enclosed in a metal container at minimum. There is no restriction of fuel cell capacity or dimensions of the fuel cell, except where otherwise specified. The installation of more than one cell is permitted.
1. Installation Internal body panels may be modified to accommodate the installation of fuel cells as long as modifications serve no other purpose. If installation includes encroachment into the driver’s compartment, a metal bulkhead must prevent exposure of the driver to the fuel cell. The fuel cell must not be installed any closer to the ground than 6 inches, unless enclosed within the bodywork or OEM floor pan.
a. There must be a metal bulkhead between the driver/passenger compartment and the compartment containing the fuel cell. This includes fuel cells that are flush mounted with driver/passenger compartment panels or otherwise exposed to the driver/passenger compartment.
With that being said the bulkhead rule between the fuel tank/cell came well before the metallic tape many of us use today. Many Spec Miata's are illegal when they would be checked to this rule. Nope, don't need any comments about not following the rule making the car more competitive or how many fires have you seen because no bulkhead. How many remember the posted video a year or two ago of the Spec Miata cockpit instantly engulfed with fire, for a leak of some sort other than the bulkhead. When your a$$ is burned it's gong to be very painful at the very least.