^looks great!

If I had a red Z, I would go with the red knob, too. Adds a nice pop to the interior.
So it looks like the collar/washer is the culprit. Only follow my grommet advice if you want to also achieve a tighter seal between the knob and the shifter boot.
__________________

Rain, snow, sleet, hail: 2009 Mazda 3 sGT HB
Everything else: 2009 370z, PW Touring 6MT