when I went to install a custom shift knob, I discovered that the default shift knob doesn't twist off, nor does it have a pin. Is there anything I'm missing, here? [like, cutting off the bloody rubber cover?]

look for a hex screw somewhere near the bottom of the knob itself closest to the ac unit and radio, ill go look on mine and let you know

i drive a spec v and it unscrews, i had a 99 gxe automatic and it had set screws, i think phillips bit, if you dont see bolts it probably unscrews

Manual transmissions - the shifter knob definitely unscrews.