The term "Repack" in the modding community generally refers to an archive that has been compressed or reorganized for easier distribution.
Most realistic packs require the Emergency Lighting System (ELS) mod to allow for pattern-controlled strobes and sirens. gta 5 police car pack oiv repack
Method B — Add as DLC (preferred):
: If you don't have it, get it from the official OpenIV site. The term "Repack" in the modding community generally