In the USA, RV means Recreational Vehicle which basically is a motor home where you live for brief periods during vacation.
I saw the movie "RV" with my wife about a month or two back, in TV. This movie acted by Robin Williams (Bob Munro) is about Bob hiring a RV to take the family on vacation and he is not familiar with using RV and gets into lot of funny situations. Not a great movie, but certainly a clean fun movie that can be watched with family & kids.
Robin Williams will always be a great actor and this movie just confirms the tradition and we see Robin in another splendid movie. Congrats Robin and live long and prosper!!!