Thanks for your post. It looks like the physics of your antifreeze explosion is probably more similar to that of of a grain dust explosion than that of gasoline which exists as a vapor. The small particles from the mist have lots of surface area and can become quickly oxidized. I am not convinced that such a scenario existed in the garage. The vapor pressure of antifreeze at 20 degrees is likely quite low and not sufficient to cause an explosion. The pressure in a cold radiator would likely not be sufficient to make a mist of leaking fluid.
I guess I’m not convinced that the car lights and cooling fluid started the fire. However, once the fire got going enough and burned through the hoses it may have added to the flames.
Lady starts backing, zig zags car, hits a workbench just so and she gets the requisite pinhole punctures.
The rest is on auto and she dies in a sudden flashfire right inside the passenger compartment!