Anyone try Meguiar Accent Dressing, comes in an aerosol spray. I also believe Duragloss has a similar product.
I've used the Meg's product on outside black trim (on the front facia and side facia) where it was almost impossible to reach by hand and had good luck with it. I was going to use it for interiors but I have not had the occasion to use it yet, and unfortunately I don't have access to the Meg's Accent dressing right now. But I am planning to order either the Meg's or Duragloss product in the near future.
But I always blow out the vents with compresses air, (LIGHTLY), and wipe down, and they always seem to look pretty good. But my interiors are never that dirty that I have to spray liquids on the vents, I would think that would leave streaks and be a PITA. And I also use a steamer to clean interior which works great for vents with the combination of compressed air. Lately, my clients are telling me they don't want ANY SHINE on the interior, so I'm not sure they would even want the vents dressed :nixweiss .
But for my cars, and the majority of people, I think it is a great idea. If anybody has used thse products, let me know how they work on vents before I try it on my car.