Border of Black Dots on Windshield

Most, if not all, recently manufactured automobiles have a border of black dots on the windshield. The dot pattern varies in width from ½ inch to slightly more. In the location of the rear view mirror, the pattern becomes wider. The rear windows often has these dots.

What is the purpose for these dots?

I always assumed it was the radio antenna.

This site says it’s something for an adhesive to grip. Others say it’s only for additional shading.

I had a similar thread about a year ago. somewhere in the archives. I think the consensus was that is was for shading and it was called “frit”. My question was slightly different in that my 08 toyota has an asymmetrical pattern (Frit on the right but not on the left)

Shading. It also a decorative touch for the black area that covers the windshield adhesive and the rear mirror mount.

My car has a block of dots above the rear view mirror, presumably to protect the electronics from excessive heat.

Not really. Your sun visors don’t really cover over the rear view mirror area. Driving toward or almost toward the sun can cause blinding light to come in just slightly above the rear view mirror if conditions are just right.
By putting black shading in front of the mirror, this is prevented.
Strictly a driver / passenger comfort issue.