This mod allows the slick top version of the Vapid Stanier Police Cruiser to spawn along with the 2 light bar versions without removing anything whatsoever. Recommended for use with these two mods.

This makes them spawn in-game: https://www.gta5-hub.com/misc/the-sixth-star

This makes them patrol around the city randomly: https://www.gta5-hub.com/misc/cops-back-on-the-beat