Extinct

I'm fairly new to using and installing mods, though I thought I had a decent understanding (since I've installed other mods which have worked fine) but after I installed this package (as per instruction with no issues) the installed vehicles don't seem to be added as a new option to use in game for patrol ? Its all still the same default GTA V / LSPDFR vehicles ? Did I miss something or was I supposed to add a line to the startup.rphs file ? Side note, thanks for the Mod, as I see the amazing quality via numerous videos and live streams my son and I have recently watched. Now I am just dying to get them working. Thanks