For those of you who have the unenviable task of washing some friend-of-a-friend-of-a friend`s vehicle that looks like it have not been cared for, you KNOW what those outside seals will do to your wash media-of-choice to become BLACK-stained or when you wipe it dry how those black streaks appear on your nice drying waffle-weave microfiber towel (or chamois, if you are old school). I use Meg`s D101 APC to clean those seals FIRST before washing a vehicle to avoid this "problem". I prefer to treat them with Aerospace 303 Protectant, but I think, like many of you have experienced, that it washes off in the first rain and streaks the paint. I`ve tried using Meg`s Ultimate Black Trim Restorer, but its better suited to hard vinyl than rubber.