A:Answer you'll need a data connection on your tab to use android auto. you can listen to your tunes thru usb, i'm assuming that the unit will read your tab's hard drive. spotify, maps and other online services need a data connection to function (does your tab have a sim card?)
i've tried to use my android phone on android auto simultaneously with my ipod thru bluetooth to listen to my tunes, but it's tricky and not always smooth. android auto is always trying to take over both bluetooth and usb. i think i got it to work once, but haven't tried it since.
great unit! there's a little lag with navigation, but you get used to it and can accommodate.
with android auto you can listen to many radio, podcast, music play apps. just check which are compatible with android auto and install them on your phone, and you can probably largely duplicate what you get from your tab's hard drive. i assume the same is true of iphones thru airplay.