Review on Car Speaker Mounting Brackets with Wire Connectors - Compatible with Various GM GMC Models, Fits 6", 6.5" and 6.75" Speakers - Check Compatibility List Below by Greg Quinit

The material is thin and soft, so it is very easy to install without being square. Once it is aligned, the four outer screws you will most likely be using do not have enough material to properly fasten the screw. There is also not enough room to use high-speed clips. Finally, the four screw slots aren't evenly spaced, so they don't work very well for drivers with concentric holes. Metra and Scosche were nowhere to be found, so I brought them in to get the job done quickly. Now it's fixed. The speaker adapter harnesses fit and seem decent enough. There are no complaints about them.