How about a way to make it possible to toggle a Wendyflag from inside the car? For the 'oops I forgot to flag this' moments as well as when Wendy says 'you thought I liked this? It sucks!' and also when listening to new music 'oops, I didn't realize this had profanity in it. Definitely not kid/grandma safe'.
Actaully in general I'd like to be able to do more actual data manipulation while in the car. Delete songs/tracks. Build and ave playlists into the main Playlists menu (yes, I can use bookmarks, but there's no way to then transfer them to permanence in the playlists menu... maybe a press-and-hold-down option on a bookmark that lets you copy its playlist to the main playlist top level?) Define custom soups. Rename tracks/albums/tags etc. ('hey I typo'd! man I have to remember to go track that down...') For text input I suggest the knob rollis thru the letters and right-button moves right when its selected. left button moves back. Like in arcade games... no it's not fast, but hey, it's meant for when you don't have a computer handy.
Anyway, just my random desires. Worth less than they cost you, I'm sure.
--pj