Since on the car player, all of the albums are mixed in together, it seems more natural to sort them by title.
I haven't seen the Soup stuff working on the car player's front panel yet. But I have to say...
If I go to a Soup view for an album, and pick that album, and it plays it in alphabetical order, I would be very very unhappy and would immediately report it as a bug. This was the number one complaint about the Rio Receiver, and if I recall, it's the one on the top of your To Do list on the Receiver.
If a soup-selected album is not playing in "album order", will there be a method available for correcting it?