Quick dumb questions for a dumb idea.

Several different ways to interrupt start. In the 74 model a seatbelt interlock interrupted the positive ( yellow wire ) path to starter relay coil. Neutral safety switch interrupts negative path ( brown wire ) in all automatic trans builds. So rather than have 12 volts at the lighter, route the neutral safety wire to it. Key turned to start and nothing happens unless lighter is pushed in providing a chassis ground path for the starter relay coil.