You can apply wax on top of the film. You have to only take care to make sure you take care around the edges of the film when you pressure wash or apply wax. The pressure jet could affect the edge of the film if you are really harsh and the edges of the film will retain some wax if you are not careful when applying it in that area. Otherwise I cannot see a downside. I had mine done a few days after buying it and it is still completely perfect. They even do a super strong thickness for the sides to prevent shopping trolley paint damage. Dents will always come in if the bang is hard enough, but the paint will not be compromised.