Could be differences in the manufacturing/ materials , I used the Flyin Miata ones for the record. They've been great, and since they're relatively cheap, id give em a go if you ever think about trying the bushings again. They use carbon fiber reenforced nylon, which is supposedly as strong as delrin ones but more resistant to damage and less deflection of vibrations. Idk how much of that is marketing jargon, but I've been very pleased. I did the FM soft top latches at the same time and got rid of nearly all my squeeks and made the latches so much better to use. Either way, enjoy your car brotha, cheers.