Accorind the the NHRA rules,which is what the track near me uses when teching in a car the rule is as follows.
"8:4 MASTER CUTOFF
Mandatory when battery is relocated or on any vehicle running
9.99 or quicker. An electrical power cutoff switch (one only) must
be installed on the rearmost part of each vehicle and be easily
accessible from outside the car body. This cutoff switch must be
connected to the positive side of the electrical system and must
stop all electrical functions, including magneto ignition. The off
position must be clearly indicated with the word “OFF.†If switch is
“push/pull†type, “push†must be the action for shutting off the
electrical system, “pull†to turn it on. Any rods or cables used to
activate the switch must be minimum 1/8-inch diameter. Plastic or
keyed switches prohibited."
Since my battery is relocated to the trunk I believe I fall in the group that needs one.