Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!
You can get SD cards and USB flash drives dirt cheap. I much prefer those options to an aux input because you don't rely on the battery of whatever you're using to output to the head unit.
If it's a screen I'd presume if there was an aux in rear then there would be an icon on screen (if touchscreen) that would be grayed out, or a source would show aux also, what's make/model of stereo?
If there's an aux source and no iput on facia then more than likely be rear input, some are RCA-Aux, and some are 3.5mm, no way of telling till you pull it out