2009 Tacoma OEM stereo wiring for bluetooth

I have a question, I pull my stereo unit out last night, and there is five set of wire plug into the unit, Antenna, 1,2,3,4 set wire
Can anyone here can tell me what are those wire for? Anyone have any wire diagram for the stereo? Like color code of the wire, what is it stand for? because I want to tap the AUX wire to have another input.

Also I saw a bluetooth handfree kit OEM that sell on ebay for a 08 Tacoma. it look like plug & play, So I try to pull out the stsreo unit make sure it will fit to my 09, but when I pull my unit out, I don't see any more space left behind the unit.

And this is the other reason why I want to see the wiring diagram for the stereo.... try to find out what I can do.

Please help.....

 

here are some wiring diagrams i found for an 06, but i know that the 09 is when they started adding the aux input, so the stereo my be different. I've always used Scosche. They makes a lot of wiring harnesses and adapters to mix factory and aftermarket equipment, and they have some bluetooth products.