My girl turns sooky and laughs but laughs hysterically at everything when she is tired but my boy will go hyperactive and will end up being a right brat.
I find if I am out and they won't get a chance to sleep for a while, I will try to keep them busy and in good spirits until they're in the car/home and they can crash.
Keep in mind they're 2 and 3 so they're not little babies anymore. With little babies I can only recommend putting them to sleep!!