Originally Posted by dad

Try a liquid degreaser-Stand away from the car- spray it on a towel-just enough to get the towel wet--"but not soaked or dripping". "Carefully wipe the window, with the towel , not touching the car body"! It will streak and smear, leaving a film, let it dry! " Now clean it with any windex product"!
Didn't work- Repeat again!
"Make sure your towel less hand doesn't get degresser on it, and touch the car body"!