Back when my Fiero had an automatic transmission, I shortened the auto shifter so it wouldn't smack into the cup holder when I put the transmission in Park. Plus, the shorter shifter looks better. Basically all I did was chop off the top 1.3" or so (i.e. three "beads" off the plastic plunger rod), and recreate the slots and grooves on the shortened lever. I used a hacksaw to chop the lever, and a Dremel tool with a cutting disc to make the slots.
Here are a couple old photos of it. The first photo shows the "beads" cut from the plastic plunger, and the metal removed from the lever. The second photo is the shortened shifter, with new slots cut for the shifter handle and retention clip.


When I swapped in the Getrag 5-speed, I gave the auto shifter to a local Fiero club member. He seems to be pretty happy with it.