car MDI audio mystery

[lesir]

Hi, i bought me a Galaxy S3 and i plugged in the unit in my 2012 VW GTI through the system port.
my question is i can play music with "bluetooth" but also on the "mdi" port.
here is the issue:
on MDI, i get music that i have no idea where it is coming from; shows up on radio display like:
601.mp....631.mp and so forth
i have none of that music anywhere in my phone!
i do have satellite service.
Would anyone know the mystery?

 

[lesir]

Well for all who have read this thread, i found out the reason for this mystery.

Come to find out,
i had lots of stored music on Google play and without even having them on my Galaxy s3, as soon as i plug-in the cellphone to the car, the car/phone picks up the Google play signal and shows all my music right on the radio display; no need to download music to your phone !!!! awesome GOOGLE/ANDROID

 

[steveh552]

Not awesome if you don't have unlimited data. Id love this but only having 2 gig of data it would eat me,alive in overage.

Sent from my LG-LG855 using Android Central Forums

 

[m4f1050]

How did you get it to work with your S3 (jelly bean) and MDI? I can't get mine to work, it says Incompatible device or something similar.