A friend of mine with a Citroen AX Sport asked me to make some centercaps since they are unobtanium nowadays. He gave me one I could use as reference, but it didn't fit with the modern wheel bolts he was running on the car (see second image I uploaded) so I made a design which can be used with regular bolts. I also added the period correct logo and printed it out of Nobufil PETG-CF and it came out gorgeous. At the point of writing this, he ran the caps on the car for almost a month now and so far there haven't been any issues. If you use those fancy impact sockets with a plastic cover, you might have to remove the plastic cover to tighten the bolts.
Update on the PETG-CF caps: Still fine on the roadcar, they bent out of shape on the racecar after several laps, probably making some more out of PA12CF.
Model Update:
Forgot to merge the bodies, did that and added a version without the logo!
The author marked this model as their own original creation.