I'd have to think the standard stereo would have a 3.5mm aux-input jack, for MP3-players/media-devices/smart-phones/etc to allow music/sound to stream (not necessarily control the head-unit remotely w/ menus/lists/etc).
Even the most basic econo makes/models nowadays come w/ that type of input.
And if there isn't such an aux-input jack, there are many after-market solutions (aux-input converters) for smart-phones & external devices, generally $75-$100 which are make/model dependant & allow streaming of music/sound to the head-unit.
With all that said, there may also be a stand-alone optional MB OEM accessory allowing such (that isn't listed on the circulating dealer pdf).