wiring a toggle switch

Niether of those is correct. You don't bring 12V with the potential of 100+ amps into the cockpit when it can be easily avoided. A small nick inthe insulation is all that's required to cause a huge short or much worse. Here's a diagram of how a toggle switch controlling an electrical device should be wired. Only the toggle switch is inside of the car while the power feed and relay remain in the engine compartment. It takes very little power to operate a relay and wires going to and coming from the relay can be tapped from an already fused source at the fuse panel.



This diagram was for a door lock actuator but applies to just about any thing else you'd like to power with it. A fuse (if required) would be run inline of the positive lead between the power source and the device you intend to control.

The other nice thing about this kind of setup is that you can also wire the relay to an ignition switched power source so that the device you're operating can not remain powered without the key in the "ON" postion. That tap would be between the switch and ignition power. You need only swap the locations of power and ground to opposite ends on the diagram above.