For reference, my shift knob snaps into the indented groove in the shifter and the boot comes right up next to the knob. Not sure what kind of new knob you got, at they're supposed to snap into that groove thing.
<span style='color:green'>1994 325i </span>- - - 75,000 mi.
No mods - - - very happy as is!
<span style='color:green'>1995 525i </span>- - - 154,000 mi.
No squeaks or rattles... unreal!