Here is my work on installing a 07 head unit into a 06 Outback wagon to access the Aux input connector:
Purchased the 07 Head unit on Ebay (P-204-UN, single CD, Manual AC, the best $50.00 I ever spent).
After reviewing all the post about the pinout of the 07 vs 06's small 8 pin connector, and since I have manual AC. I determind that the existing connector plugged into the existing 8 pin connector of the 06 head unit would not be needed. The car does not have a sub woofer. NOTE: For the Auto AC control guys you could populate pin 8 on the made up connector and run a wire to pin 8 of the orginal connector. You would have to determine the best way to connect it to the existing connector. Molex makes a headder that has the same pin size as the orignal connector. That might work.
I determined that the pin to pin spacing was the same as the Molex 0.1" space header plug (CONNECTOR PART NUMBER, MOLEX 2695-4, Allied Elec (no stock) and that the row to row spacing would allow two of these connectors to be stacked one on top of the other. I felt that covering all eight exposed pins was better than just getting the 4 pins necessary for the Aux input. NOTE: You can purchase a plug with more than 4 pins. This connector is very easy to cut down to the pin count you want. Radio Shack may also stock a type of the connecor.
I took two 4-pin molex header plugs placing then one on top of the other to make a 8 pin plug. I then took a standard 6ft long 1/8" male to male stereo audio cable and cut one end off to get to the three wires. Crimped the three wires to molex pins (PIN PART NUMBER, MOLEX 2759 (Allied Elec 863-0855 ) and inserted them into the correct location (can be found on other post). Pin 1 (Left Audio), Pin 2 (Right Audio, Pin 5 (Audio Gnd). A 4th wire goes into Pin 6 (Aux enable) which is connected to chassis thru one of the small screws of the head unit. I then put shrink sleeve arount the body of the connector to hold it together, but that is not necessary.
Next I took an sharp knife and cut down the two ridges that the 8 pin connector of the head unit has. The two ridges are there to help the orginal connecor slide in easy. They need to be removed to allow the made up connector to slide in.
I tested this set on the bench and the aux i input worked. I installed the head unit this weekend (orginal 8 pin connector in harness not installed), routed the aux input cable to exit the center console on the passanger side, leaving approx 2 ft of wire. Everything works great.
SEE Post 265 & 266 for PHOTOS of the Aux input mod.
SEE Post 269 for Molex connector info