When I went to install my Diode Dynamics headlights for the 2015 Civic SI, I noted that their adjustable collar did not provide enough offset to allow for the screw heads. So the bulbs just wouldn't lock in. I got out my micrometer and got to work reverse engineering it. The result fits like a stock bulb in the slot and works great!

Note: DO NOT PRINT IN ANYTHING BUT MATERIALS THAT CAN HANDLE HIGH TEMP.

I had these prototyped in PETG and they melted after three weeks while I waited on my Nylon 12 SLS prints to come in from Xometry.

UPDATE: I ran these lights for 6 months with the nylon rings and it didn't give out or even warp. It could use some dimensional refinement but it held well.