I've left Finn in the car before. If I just have to run in and out of a store or something, usually less than five minutes. I have, though, left him in the car if I've stopped at a Wendy's for lunch or something...but, I'll only leave him then if I can park near a window and then sit near the same window. but, I've only done that a couple of times. I don't think it's that big of a deal, as long as it's not extreme weather, one way or the other. When I travelled from Texas to South Carolina, he obviously had to stay in the car every time I stopped to get a drink or use the restroom or whatever. And, for daily trips and stuff, I'd rather take him with me and have him wait a couple minutes alone in the car than stay at home alone while I'm gone. It's more fun for both of us if he goes with me.