My car does this too when I plug my phone into USB, it starts playing the first song alphabetically no matter what. I became so sick of this I just have a long empty track with tildes in the name in my library. I would assume bluetooth would do the same but my car's bluetooth has been off since it came out of the facotory and I will never turn it on.
Another obnoxious design is if i want to start a playlist I can't just start playing it - It gives me the playlist sorted alphatically. Once i start playing a track it then sorts them by playlist order. Literally the point of a playlist is the order which you choose your songs to be in. Same solution works, put a short empty file with a tilde, 0 or underscore. So when I pick a playlist I just have to press enter twice and not deal with the alphabetically sorted list.
This trick also works when i try to navigate with google maps and my phone is plugged into usb. I wont get the navigation voice if a music track is NOT playing - again I go to my silent track and play it in order to get the navigation voice when my phone plugged into USB