iPhone 4S fails to connect to car USB following v6.1.1 upgrade

After upgrading to iOS 6.1.1, my iPhone 4S is not recognized by my car's head unit USB. It charges and tries but reports, "Cannot play".

Is it at all possible to rollback the iOS? The internet does not think it is.

If not, I this will be my first and last iPhone.

Every other software vendor makes backing out of changes pretty easy. Why Apple?