I left DD3 sleeping & DS at home alone yesterday for 3 minutes while I ran the girls lunches up to the school for them.

I would leave DD asleep in the car to get the bigger kids from school. But I would park where I can see & I am only 5m from the car. I never get my kids out at the servo. Its different here where nothing takes longer than 30 seconds & you're always with in metres of the car though. That said, if I'm somewhere else, in a city or whatever, I have the older kids all with me. The only place in a bigger town I would leave them in the car though would be a servo. Every where else I'd get them out, sleeping or not.

I also used to leave DD sleeping in the car for DC drop off or pick up. I couldn't see her then, but the DC was up a long driveway behind houses & out of the way & I knew I wouldn't be longer than 5 minutes, with windows down & doors locked.