I leave the girls in the car, but always for a quick stop. If I know I will be more then 5-10 minutes they stay home. If I get inside and it will be more then 5-10 mintues, (long lines etc) I would take them back home and stop later. When I can, i try to make at least 1 stop that they can get out...the pet store, a park, the dog bakery...somewhere o the trip is for them too. Also, if if is at all hot out they stay home.