18.0.E.3. Driveshaft Hoop: RWD DM and EM vehicles shall have a drive-
shaft hoop capable of preventing the shaft from entering the driver’s compartment or damaging any
fluid or electrical lines in the event of joint or shaft breakage. All cars in competition us- ing
open driveshafts must have a retainer loop with 360° of en- closure, ¼ inch (0.250”; 6.35 mm)
minimum thickness and 2.0” (50.8 mm) wide, or ⅞ inch (0.875”) x 0.065” (22.23 mm x 1.65 mm) welded
steel tubing, securely mounted and located so as to support and contain the driveshaft in event of
U-joint failure. Vehicles that have a closed “tunnel” or other such structure which the driveshaft
passes through such as the vehicle’s frame, may be considered for an exemption from the SEB if that
structure meets the criteria stated above.
Note: DM and EM vehicles are exempt from the scattershield,
driveshaft hoop, and Master Switch requirements if they are using
DOT-approved tires.
Bold for emphasis.

Could well be that the bellhousing counts as a scattershield. Either way, DOTs reads to me as not needing the switch.