Technical Rear window garnish holes question???

So on my rear window moldings on my 27 REO there are two holes on the top of each side... what could these be for?
your help is appreciated...

 

Window shade ...

 

roller shade...you can get them at lowe's cut to size I had to get a new one for the back of my Airstream

 

Window shade as others have said. Because such cars have vertical windshield and back window, reflections can bounce around like crazy especially at night. The shade was to block the headlights of following cars.

 

cool thanks !