Oh that is so fun! We did that for my birthday one year too! And yes talking is a great idea!
They usually have radios and drinks in limos so if you get too bored just turn on the radio singing is fun! I doubt that you will have to entertain sixteen teenagers in a limo they are ganna be too excited they are in a limo to worry about that.
Talk, if they are really friends you can entertain yourselves talking.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.