I am making a Carrot cake with Cream Cheese frosting for a customer. They are going to travel with it (aprox 2 hours) to the party. How long does Cream Cheese frosting last out of the frig? Should they put it in an ice chest?

it really depends on the perticular recipe. But safely should be about 4 hours. That of course depends on how hot it is where you are, the hotter it is the less time it will survive out of the fridge.