In my experience the easiest way to do it is to use the ae64.com harnesses. They provide a 16 pin connector for camera and 6V power as well as making an accessory 12V harness that plugs into an unused plug behind the radio ("Option harness"). With those connectors you just plug the camera video to the 16 pin harness, plug power and ground to the option harness, plug the reverse wire into the big harness in the footwell and the other end to the 28 pin harness on the radio and run your wires (in my opinion running the wires was the hardest part).

I used bullet connectors for everything so I didn't permanently modify any wiring (other than the splice for the reverse wire). I also extended all the wires in the main camera harness to be the same length as the power and ground were much shorter than the video signal. Snaked them up the trough under the panels on the driver's side, through the rear seat and around the trunk lid to the cam. Really wasn't that big a deal.

Using the option harness means your camera is on all the time when the accessory is on. Probably not a big deal but mentioning that in case it matters to some.

I hope it worked perfect for you. @2k15BRZ
I will be installing mine today!

any updates? @mixedjuice

sounds like @czechm8 find a easier way to do it but can you explain better...? Cuz i really wanna do this but I have zero knowledge on wires & stuff...

@chaoskaze
yeah i finished my project. the lines turned out pretty good. of course not factory lined up perfectly.
but very useful and still very flush/clean installed.

Post a pic of the cam and actual output of the head unit please :o

coming up! just gotta get this to work on my mobile phone

Here are the 3 pieces that plug and play together.
1. 16 pin harness that plugs into the back of the headunit.
2. male to male video cable with power wires on each end
3. female video input cable attached to a camera with power and ground wires.

remove headunit
unplug factory 16 pin harness
plug in new 16 pin harness
plug original 16 pin harness to the extension of the new 16 pin harness
plug yellow male video input into female input
tap red wire to a 6V+ wire on the factory head unit. (i used the ACC/yellow cable)
run the wires to the back of the car, under all the carpet and trim
plug the other end male video input to the camera output video
grimp the 2 red power cords together
ground the black wire
drill a whole to the back fender where the camera will go.
screw in and adjust
finished

upon starting the car, place in REVERSE, camera should power on once in gear

It's interesting on the camera vertical range, can you see directly behind you? I had to hack mine to be able to see directly behind me. But I do get a bigger picture overall as I no longer have 1/3 of my screen showing the bumper.

The camera actually looks very similar if not externally identical to mine which I got off eBay.

@a_dee
i can see directly behind me, but with an angle. how the camera is angled coming from a straight install it does show the portion of the bumper.
there is a white cord the is the angle/mirror cord that i kept on. (i didnt want to cut it)
but i did cut the green cord that had parking lines in it.

What kind of hack? I am interested to see if this can help my current angle.

I made a shim to change the angle out of rubber (jeweler's bench block), pics attached of before and after.

Looks like i need to fabricate a little more!
awesome solution man @a_dee

how is you build doing? im looking into buying a used (4k miles) perrin performance exhaust. But still cant get myself to buy it coz i am looking for rims and tires more