Finally done and fixed (most) bugs. Sometimes it spawns without a lightbar, as a 'slicktop' police car, sometimes it spawns normally. Only has 1 livery enabled, I'm not quite sure how multi-livery works yet. Lightbar has corrected strobe pattern, is Non-ELS and the model is as low poly as a default car. A special thanks to SkylineGTRFreak for providing the civilian model unlocked and all his GTA V converts!
*Read the read_me for 'installation' instructions.
*Is now multi-livery enabled. Make your own skins however using the template.