Yep! That's what you need. And these are also what you need to hold on any of the wide lower body moldings like the ones they use on the Limiteds.
And you do need to remove the glass to install these correctly. Now might be the time to upgrade the rear glass to rear window defroster if your car doesn't have it. The rear window is the same in all 78-88 G-Bodies. Just make sure you snag the purple power wire and make sure the ground wire is good.
And a few of us vendors sell the switch and correct trim applique for the Regal.