Pic#1: I installed the Leptronix kit in my 2005 Outback Wagon with a single CD unit over the weekend. Kudos to Sebastien for such an excellent product!! It works great and I had fun installing it.
Pic#2: The Leptronix board in the single CD unit with the remote switch and audio cable attached.
Pic#3: The location of resistor R291, which needs to be removed (for the single disc unit only). Refer to the 2.5i installation manual in the Leptronix website for details.
Pic#4: Thanks to CatInTheDryer's idea, I put the remote switch in the cupholder. I highly recommend the remote switch. Without it, you have to wait about 30+ seconds for the "auto detect" to switch between radio and aux-in, which feels like forever.
Pic#5: Cut some plastic off from the cradle for the seat-warmer control to get clearance for the remote switch.
Pic#6-9: Thanks to absolutsnwbrbr's idea, I installed an audio jack (from RadioShack) next to the 12v outlet in the armrest compartment.