I have a 2009 Mazda 6, and within the past few months it has developed a "hairline" crack in the soft, vinyl side of the dashboard; I'm not 100% sure it's vinyl, but it's some soft plastic material that is thick, not the hard plastic molding on other parts of the dashboard. The crack is very thin, but large. I purchased a tube of the Gorilla Glue brand silicone caulking, but the tip of the tube was much too large to get the caulk into the crack. In the end I was left with a crack covered on the surface by the caulk. However, the caulking is easily just rubbed off with your fingertip, so now the coating of the caulking is not even there.
Any other suggestions for how to fill such a thin crack to prevent it from worsening?