Replaced the OEM Fusion MS-EL602B rear speakers with a pair of Rockford Fosgate T16 Power 6" 2-Way Speakers.
Utilized a 5" diameter hole saw drill bit.
Covered the holes with an 18ga. 5005 Satin Black Anodized Aluminum 6" x 6" Plate.
If choosing to install this particular Rockford Fosgate T16 Speaker please note that it has a directional pole-mounted tweeter that when installing you will want to orient this speaker so that the tweeter is pointing toward the front of the rig.
I included Image #4 to illustrate that this particular speaker design with it's 1.93" top mounting depth comes within approximately 1/16" of the bottom of the aluminum cover plate once installed...a very close tolerance, but perfect fit.
I'm in no way, shape or form an audiophile, although I can discern between good or above average audio quality vs. mediocre audio and have felt for some time that an upgrade to the OEM Fusion speakers were needed. My son who is working on his Masters in Acoustical & Audio Engineering approved of this speaker selection for it's price point. All I know is that with the speaker balance shifted 100% to these rear speakers that they sound excellent. I'll be replacing the front two door speakers very soon.