In all seriousness when the creators think it's ready and whenever they want it to. This question has been asked a lot. People don't like it, I can see why but we can't control other peoples actions but if you don't ask and be patient that would be a big help.
That applies to basically everything. If there is no release date, that means there is no release date.
According to LJ only the last set of wheels and thumbnails are on the to-do-list, so yeah, very soon (at least sooner than Career Mode lol)
japanese =/= jdm --- Post updated --- "only" wheels is a bit of an understaement, wheels take effort and skill and can take quite a while to make good
The wheels were finished a while ago but some extra things came up, refreshing some old content but that shouldn't take too much longer than before