This model replaces the chrome cap of the BMW coupe E92 extender arm with a hook that grabs the seatbelt successfully much more often than the original design. Designed to be a near perfect fit with the OEM shape.

I recommend printing in ASA or ABS for the high temperatures in a car.

The OEM piece easily comes off with a pry tool, then you can attach the 3d printed models with a strong double sided adhesive (https://www.amazon.com/Gorilla-Heavy-Double-Sided-Mounting/dp/B082TQ3KB5)