Then you'll have a "mist" all over the place. The water then fractionates out first because it's condensation temperature is different than ethylene glycol.
Basically, the water component will condense on the walls of the garage and the cold metal of the car leaving behind an ethylene glycol mist.
Then, in the early morning when she comes down to start the car she has an ethylene glycol "mist" inside her car, in the garage air, and wherever.
I think that gives you the lower ignition temperature you were looking at ~ and there are two possible sources ~ (1) the lights, or (2) the special high efficiency BMW catalytic converter (I believe this is unique in the automotive industry).
Yes, if the antifreeze is very hot it will spray, and if it is hot, water will evaporate until the mixture reaches an azeotrope point (which is where you want your water-glycol mix to be, to get the lowest freeze point and highest boil point).
It should not distill out completely, though. But I’ve read that a water-glycol mist can burn in some circumstances.
I’m just gonna have to take my garden sprayer and do some experiments with my Bernz-O-Matic.