I plan to buy about 6 live lobsters for New Year's dinner, but I have to drive about 5 hours with them. So I need to keep them fresh while driving and then for about 12 more hours before cooking. I can't buy them tomorrow because stores are closed.
Any suggestions?

You could bring a cooler with some ice for transport. As for storing, I usually freeze them before eating anyhow. That way they are not alive when you put them into the boiling water.

Yeah I do the same thing when I go crabbing. I catch them fresh put a bag of ice on them for the 2 hour trip. Then put them in the freezer for a few hours then cook them.