While surfing the interwebs looking for something to clean our shower from calcium/soap scum/water spots/etc (w/o getting high off chemical fumes) and came across people using glass top cleaner. Never crossed my mind but makes complete sense! Tried it on the shower and it came out like new. Haven't had a chance to try it on the car windows but will definitely post up pics (this weekend?) of results. You can pick some up at Target and a little goes a long way. As usual, don't let the scrub pads touch your paint.

 

Interesting...thanks for sharing!