ACan I use plastic wrap on fondant cake when traveling to keep it covered?

yes.  

I fly with fondant covered cakes several times a year. 

I don't like anything touching the surface of the cake because if there's any moisture present, creases in the saran wrap will then mar the fondant finish.  I just put the cake into a fairly tight fitting lidded box. Works perfectly.

AA sealed box of the exact cake size will be enough, what if the cake is covered with decorations how would you wrap that ?