Thanks, Cees. You're probably right, and it turns out I don't have a trunk light. That whole square panel in the rear of the compartment is missing, somebody probably took it out complete with the plunger switch, which I also can't find.
Do you happen to know if this wire is supposed to go in the aluminum carpet channel together with the main harness? Or just under the rug? It's a very tight fit in the channel and doesn't feel right.
-Dave