Owen makes it pretty clear when he's had enough of his car seat, baby seat, or any other seat these days. He plants his feet and arches his back to try to get out. In his baby seat, he works his way down till his legs are hanging out the bottom. He's very squirmy!
He's also figured out how to roll over in both directions now, although tummy-to-back only makes a rare appearance. Yesterday he managed to roll all the way from one end of the blanket to the other by rolling over three times in a row from back to tummy to back to tummy!