My corolla won't let you lock the doors while the key is in the ignition. Unfortunately today I found out that the Xterra will, while at Babies R Us getting Amelia a humidifier. Thank GOD I didn't lock it with her inside. Just my wallet and phone. Ughhhhh. Thank god she was so good natured while we waited an hour and half for AAA.
My VW would lock, but it is an older model. I am always paranoid I will lock the girls in in my Montana, so I always leave one door open before I get everyone out. Just to be safe.