Three words: Books on CD! Makes a huge difference! With your son being 11, it shouldn't be tough to find some that please everybody.
Re those who noted the cost/time of the Auto Train: Yes, if you are on a switch-off-and-drive-all-night commando mission, the Auto Train is slower and more expensive than driving. But you will/should not be traveling that way; you would probably have two hotel nights between NYC and Orlando. The train is overnight, and, taking the train, you have zero hotel nights between NYC and Orlando. Consequently, compared to the hotel costs, extra meal costs, and extra gas, there is almost no net cost to using the Auto Train (assuming you travel coach).
Re those who noted the cost/time of the Auto Train: Yes, if you are on a switch-off-and-drive-all-night commando mission, the Auto Train is slower and more expensive than driving. But you will/should not be traveling that way; you would probably have two hotel nights between NYC and Orlando. The train is overnight, and, taking the train, you have zero hotel nights between NYC and Orlando. Consequently, compared to the hotel costs, extra meal costs, and extra gas, there is almost no net cost to using the Auto Train (assuming you travel coach).