Honestly, if warnings arent working, then I would let him know that you wont take him anywhere. Now, I am sure this might be difficult, but try to take the baby to toysrus and come back with a new toy for him (the baby.) Help your son really see that you went without him, and make him wish he could have. Then plan something and lay out clear expectations. Help him remeber as time gets closer, and then see how it goes, if he does well, let it be very well know to anyone who cares!! Maybe he can call dad on the cell phone to report his good behavior etc. Help him see how much more attention, and rewards he gets for being good. However, do remember that if he still takes a nap, say at 1, and you are trying to leave somewhere at 12:45, he is tired and wont be as cooperative, but most of the time, he can do it. Also, maybe a small treat or reward in his car for when he gets buckled in. This is how the mother of the kids I babysit gets them to go home sometimes. I know it can be hard, but good luck! ~A.~