I won't argue that a switch works for powering it off. In fact, a 500 / Autopilot setup has at least three ways to turn it off and on and none of them include unplugging a lighter adapter: Lighted toggle switch that mounts in a square cutout, a small switch that mounts in a round hole, or a sense wire that hooks to the ignition switch of the machine. The wiring harness kit included all three and wires / plugs to hook them up.

I think it has been pretty well established that the lighter plug isn't the best solution for powering an EZ-Steer setup of any type. I did use my EZ+ and EZ-Steer for three seasons, with the lighter plug and had no problems with it though. I need to wire a 500 & EZ up to my sprayer, before the season arrives. I think I'll run a heavy wire and use a toggle switch for it.