I'm sure this has probably been asked before, and I already used Google, but I feel my question is unique. While searching, all I could find were recipes from some really strange sites that were either all about doing it cheap (cheap meaning not ideal/safe for the vehicle's parts/paint/hoses) or making a safe/non-toxic alternative that doesn't handle the cold. I'm searching for neither. So my question is, what is the readily and easily available commercial winter washer fluid made with? I want to make the same exact thing without spending $2+/gal. Everything I found said either methanol, ethanol, or alcohol. I even read people using vinegar and vodka. None of the above sound safe for the car/hoses except maybe methanol (I'm no chemist). I'm willing to experiment on the cheap, but if the answer is buy it pre-made like I always have, then so be it. Just trying to save some cash because my family fleet uses A LOT of this stuff.