Looking for thoughts on where to locate the master shutoff switch. I ordered the iWire harness, but that locates the switch on a center console panel which isn't easily accessible from the exterior in a crash.

Per SCCA GCR:

The standard locations shall be
as follows:
A. Formula and Sports Racing Cars–In proximity to the right-hand
member of the roll bar, but in a location so that it cannot be operated
accidentally. It can be mounted on a bracket welded to the
inside of the upright member or mounted so that the operating lever
or knob is outside of the body panel immediately in-board of the
upright member. This is the standard location on Formula cars built
to the Constructor’s Association requirements for Formula 1.

B. Closed Sports Racing Cars, Production Cars, Improved Touring and
GT Cars–In front of the windshield on either the cowl or on top of
the fender, but close enough to the windshield to be accessible
if the car is overturned. Alternatively, it may be mounted below
the center of the rear window or on a bracket welded, clamped
or bolted to the roll cage or dash, easily accessible through the
open window. (Drilling of holes in roll cage to attach the bracket is
prohibited.)

C. Open Production, GT, and Improved Touring Cars–May exercise a
choice among the above locations.
Our regional race organization (ICSCC):

D. Circuit Breakers. All cars shall be equipped with a functional master
circuit breaker (master switch) which cuts all electrical circuits except
fire extinguishing and life support systems. It shall be located so as to
be both easily visible and easily accessible from the exterior of the car
if the car were overturned. Master electrical switches shall only have
one motion to turn off (i.e. turn left but not push and turn left to turn
switch off). The off position shall be clearly indicated at the switch
location.
SCCA is more specific. cowl, fender, rollbar? Any recommendations?

Jeff