this mod does exactly what it promises to do and that is to open up certain closed interiors around the map , this mod was inspired by Attramets mod: https://www.gtainside.com/en/gta4/mods/167832-more-visible-interiors/
(be sure to backup ur files before replacing)
the open interior list is same as Attramets one. I also reccomend to make new game to avoid glitches like few interiors not open