some good info from another forum:
green wire grounded (no connection to e-brake)
:start car and at "starting pioneer navigation screen" flicker your lights
:you have to hit "okay" to confirm connection is legal
:you also have to hit "okay" to confirm the e-brake isn't properly connected
:the dvd will then play regardless of the position of the e-brake
:you can switch in between navi, dvd, am/fm, and library
green wire properly connected to e-brake
:e-brake must be off
:start car and at "starting pioneer navigation screen" flicker your lights
:you have to hit "okay" to confirm connection is legal
:the dvd will not play if e-brake is engaged and then released (must restart car and redo the whole process in order to get dvd w/o e-brake on)
:you can switch in between navi, dvd, am/fm, and library
note: when i say "flicker", it means the first initial screen will show a message at the very top stating the pioneer navigation is initializing and at that very moment you turn your lights on and off. the good thing with this is they can even be your parking lights so it's not as obvious that you're screwing around. if you do it at that very moment (since this screen is on for only a second or so), you only need to flicker your lights once. if you miss that screen i would just recommend restarting from the beginning, but i also had luck flickering my lights about 5 more times during the loadup screen following the initialization screen when i intentionally missed the first queue.
to me, the best way to do it is the grounded way, because then it doesn't matter how you start the car or if you have to use your e-brake for some reason, but there is an extra "okay" screen you have to touch because it knows that it's not connected properly
this is pretty much directed toward gaspar, but i'm sure it's informative to anyone else interested in the Z1.
