The B pillar cover/finisher on my 370Z was apparently mistreated by a previous owner, and one day just decided to fall off when I brushed against it! It looked to be shoddily glued back on with silicone blobs, a poor substitute for the original clips. New ones are $90 each, and owning a 3D printer I find it difficult to shell out that kind of money for a chunk of plastic.
So I scraped and sanded off all of the two molded-on brackets, and most of what remained of the molded on pawl at the top side. Then I drew up these replacements and epoxied them on. Looks and works good as new, and better than when I bought the vehicle.
Its easy to see why they broke originally, the stock brackets are super thin and molded from brittle PMMA. the first attempt to remove them without a trim removal tool brobably broke all of them off... I didn't get any pictures of the backside after gluing on the replacement parts, but the other B pillar is probably in the same state so I'll try to remember to get some pics when I fix it!
Brackets are best printed vertically, so the part isn't stressed along layer lines where its liable to crack. For the same reason the pawl part is best printed horizontally or it could snap at the thin section. No supports necessary for the brackets printed vertically on end, but the pawl will need some if you print horizontally. materials with strong layer adhesion may not need to. I'll upload a square based pawl to make printing horizontally easier at some point. Don't grind off all of the original pawl, leave about 2mm of the + shaped base to center the replacement 3D printed pawl onto. Sand/scuff the back of the pmma finisher/cover well or the epoxy wont stick.
If you destroy the little nylon clips trying to get them out of the grommets on the car like I did, you can find them here or simply search for 76988-4N000. They snap right into the printed brackets, and then the whole thing pops right back onto the car.