i leave my kids in the car now, with the windows slightly open, but with the doors locked. i also only go to one of 2 local petrol stations, my fave one being with the bowser is right next to the doors into the shop, so i can see them at all times. but it is personal choice, its what you feel the most comfortable doing. i think its easier to get them out when they're babies coz you'll be holding them, but now that my kids are older, i don't feel comfortable getting them out with lots of other cars and stuff around....