My shit box of a car has completely borked speakers and I'm looking for a way to use a pair of Bluetooth ones as I'm not paying hundreds for unnecessary repairs on this hunk of junk. They work fine in terms of sound but I have no way to mount them outside of tape.

I was looking for something similar to phone mounts, where they have a plastic base attached to the top of the dashboard with adhesive, with the actual holder then suctioning onto said base. However, phone holders don't have the right grip to properly attach to the speakers (roughly round shaped, perhaps 7 inches in circumference?) so I was wondering if something like pic related exist with "teeth" arranged in a circle that can be cleaned down on the speaker.

Otherwise I'm open to any suggestions other than tape or glue to affix my speakers.