If you haven't read through this thread (UBER-STEALTH Under Floor Sub Install) I highly recommend it. There's a ton of good information about wiring/configuring the LC2i. Some of the best info is buried pretty deep in the thread so I'd suggest skimming through when you have time.
I don't have an LC2i, but my LOC was tapped behind the head unit. I didn't do the install and they said they couldn't get access to the rear speaker, but I think they were just being lazy.