To keep the cable short, I mounted the NHRA mandatory cut off switch right next to the battery. The shaft of the switch is oriented vertically, protruding through the floor. A 5/16 inch by 030 wall stainless tube runs from the switch lever, under the seat, back through the trunk, and out the back of the car, and as a T handle on it to operate it remotely. A side benefit is that I can reach to turn it off and on from the driver's seat. The stainless tube weighs barely more than a pound.