Thatwhatshesaid

Hey guys! i have have been searching all over the forum and i cant find the answer to my question. I am trying to set my Av sources( ipod, fm, etc...) to keep playing when the NAv voice gives direction . i know some of the unit have that options and i read somewhere that the 3.0 version has an option to let you do that by turning the radio off or on and activation the " grey button". but how do you do that with the version i have?