OP-Check out the YT video from 50’s Kid if you haven’t already. It’s called the E46 Radiator and Coolant Expansion Tank Replacement video. From about 24 minute mark, he pops in the new ET and it looks really loose, but the clip and everything else snugged into place.
He also takes off the bracket for the radiator so you can get a better idea of how everything else fits together.
Hope this helps.
Sent from my iPhone using Tapatalk