Does any of this stuff actually remove the film of plasticizer that forms on the inside of car windows in the heat? I've tried many of these approaches and dozens of products and it seems that most of them at best allow you to smear the schmutz around, not actually get it off. The talc idea seems interesting if it actually provides a better surface for the molecules that make up the film to bind to. It seems they love glass.
It seems to me to take about a decade before I can get car windows clean; it takes that long for the off-gassing of all the plastic to slow down to the point where regular cleaning can actually get ahead of it.