Sometimes I take them with me to run to the store, only if I'm going to be a few minutes. I park way away from everyone, but I make sure they can see me going into the store. I would never leave them in a crowded lot, I'm afraid of dog nappers, too. usually they just lie down or sit with their noses in the window watching for me. Winter's not a problem, but if it's hot I don't leave them in the car at all.