that's not a true speed sense, it's used for radio volume adjustment. A true speed sense will test a/c voltage and fluctuate with vehicle speed.

 

Radio, Navigation and the speedometer in the G35 all use a pulsed signal. The reference signal diagram for the speedometer isn't as detailed as the radio reference signal diagram, so I'm not sure if it's the exact same signal, but they're all 2-pulse signals, not just a varying voltage.

 

A bit more investigation and I can play DVD on the JDM screen in black and white but im hoping that this unit does the trick?
http://www.ebay.com.au/itm/PAL-NTSC-...item3f1c9035d8

I have this cable below running the iphone.

http://www.ebay.com.au/itm/NEW-USB-T...item3ccb70cb37

With this cable connected to my Skyline 350GT 2004, It will automatically play I phone music/Audio (no need to press TV or anything).
Through the TV function it WILL play my recorded Video in colour AND audio.

Now what I carnt put my finger on is why I can HEAR google maps telling me the direction where to go on the CAR SPEAKERS but no video through the screen??

Is this the software of Google maps?
Is it possible I just need to change my Australian maps to the I phone Maps APP?

I kind of don't really want to go down the JAILBREAK/AIRPLAY MIRROR APP route I can help it! If that's my only option so be it..