thats where buffing it down comes into play. However i usually wont with megs product. Don't get me wrong tho, some interiors are kept in terrible condition and will not play right when working with these protectants. Some dashes are so brittle from fade and heat damage, it is a ticking time bomb, then you will get the blame.
depending on the amount of texture in a surface, opti seal for glossy and flat surfaces, dressing/conditioner for texture, rubber/urethane surfaces.
buffing it down, and nourishing the surface with dressing will provide a uniform match. I have never really had blotchy or streaked areas. I will tend to work the product in if needed- which of course takes longer to complete a job.
Dont ever use cleaner wax, especially like zymol unless the surrondings are completly masked. That is one of the worst stainers i have ever seen into something such as vinyl.