Contrary to my belief it appears that it isn't common knowledge that cars require water to work. You don't just put it in to give the wipers something to chew over. Seriously, engine, big fire burning thingy, lots of heat, water, cold stuff, take away heat, good thing. No water, big boo boo, engine kaput, perhaps lots of smoke, walking in wind and rain for long time, mucho money to fix etc etc...

To add insult to injury, twas a mechanic driving it at the time...