I used to use Nu Finish twice a year, and it was an all day project to wax the motorhome. A friend who shows hot rods told me about Lucas Slick Mist which is a spray on wax, and I use it every time I wash the rv. Gives a brilliant shine and water beads up in the rain. It doesn't matter how long it lasts since I use it every time I wash the rv, which is at least once a month. It is a blue bottle available at Wally World for about $8, and I get about 3 waxes of the rv with it. I also use it on the cars and is super easy.