In a Moving Vehicle for 20+ hours with a Two Year Old

We're on our way to Florida tomorrow morning - in a small car - with a two year old. Have pity on me. I am sure tomorrow mid-day I'll be wishing I was at home alone with the cat and a cold glass of whiskey. Especially because Mr. Oliver (who is generally an easy going kind of kid) decided to embody the kind of behavior that earns the Terrible Twos title. I'll spare you the details and let you use your imagination.
The destination is, however, very much worth it. Oliver will get to meet his three cousins and have a blast, the adults will get catch up, snuggle a new born baby, and be happy in sunshine and warm weather - it's all good.