"Instant dislike" refers to a feeling of strong dislike or aversion towards someone or something that occurs immediately or right away without any hesitation or thought. Full definition
Their instant dislike of the article because of this seems to keep them from seeing the point. (religion.blogs.cnn.com)
Then, chief among the antagonists — I'm sure none of these people are meant to be perceived that way but let's just say these are some talented actors here — is Maggie Gyllenhaal's Clara, a nutcase who takes an instant dislike to Jon and makes life in the band a living nightmare for him. (digitalshortbread.com)
With an elaborate hairdo that could double as a Byzantine sculpture and a constant look of disdain, Byrne crosses paths with Cooper when the agent poses as her bodyguard and the two take an instant dislike to each other. (rogerebert.com)