I've had XPEL on two dark blue cars for three years now with no issues. Prepping the surface, stripping the wax/sealant off and then doing a full paint correction was required before the film was applied. The film added glossiness to the cars if anything, my two cents, and the clarity of the film hasn't changed. I was warned to not use a cleaner wax on the film as it could micro scratch the film. Other than that I've used various waxes.sealants on it with no issues.