Mocha,

Thanks for the response. As I've said before, I'm no electrician so I probably just glazed over the relay part of your diagram. What size relay should I get, and does it need to be wired to anything else, or does it just sit in-line between the dash switch and the solenoid? I'll also have to scape some paint off behind the solenoid mounting bolt to make sure that the ground is making good contact with the metal of the door.

As for the switch itself, it works like a charm. It lights up and dims with the other switches, and the red light on it even comes on when you press it. Now all I need is a second pin switch to activate the light when the rear door is ajar.