Sorry for bumping an old thread but with some updates in the adapters available I figure it's better then a new thread.
I am considering updating my iphone 4 to an iphone 5 but I have a chr 550 lockpick waiting to be installed here so I am conflicted.
After some research I realized the lightning to 30pin adapter apple released is useless for this but I noticed they also released lightning to hdmi and lightning to vga adapters.
What I am considering is:
Lightning to vga adapter
Lightning to VGA Adapter - Apple Store (Canada)
VGA to RCA adapter
VGA to S-video and 3RCA F Cable - Free Shipping - DealExtreme
I then wire the RCA to back of lockpick and Ipod cable to front of mygig. The lightning to vga adapter has a passthrough for the cable also.
I figure VGA is easier then HDMI as the HDMI to RCA adapters are massive.