forums/websites for mix track IDs ?
or what else do you do? theres plenty of tracks i cant get out of my head and maybe i’ll never get to know them…
beatportal has a section which should work for mainstreamish stuff. never posted there myself, but here’s the linky.
for more demanding questions, you can try the track ids group on discogs (you’ll need a discogs account to join the group). a considerable amount of expertise there, but they might laugh at you or ignore you if asking about something very commercial.
and then there are many DJ forums which have a track id (sub-)forum. not DJTT, though. 
also, if you heard the track in a youtube vid, nothing wrong with adding a comment to the vid.
or play the track to a guy at your favorite record store (yeah, these places still exist).
ofc, shazam and soundhound may also identify mainstreamish music.
tranceaddict.com is pretty good for house, prog and deep house (and trance of course 
)
also, google.
mixesdb >>>> 1001tracklists