Ok, I finally got this to work after months and months. i will detail instructions
Iphone 3gs 3.1.2 Jailbroken( I have a 3gS but the 3G will work as well)
Sling player at home
mobile sling on your I
3g unrestrictor to enable streaming over 3g
TVout Tuner from ROCK
(Other TV out App must be deleted...doesn't work anyway)
Set up 3g Unrestrictor to allow access for SLING
On UNIT(AVIC) go to Movies> then select a movie.
Once its playing on screen hit the home button on your I. ( Don't touch the UNIT)
Enable TVout Tuner, once this is done it will show the springboard on your U
