The Ford Focus is a workhorse of police forces across the country in my GTA Universe - with almost every police force using the Estate version of the Ford Focus. As such, you'll see a wide range of colours liveries of the Ford Focus over the country - from the blue, white, and green of the GLSP in the West Coast, to the baby blue and white of the VCP in the East.
In my videos, the Ford Focus is the 2014 Estate model by Connolly14 which you can find here: https://www.gta5-mods.com/vehicles/ford-focus-incident-response-vehicle. You can see all the mods I use in GTA 5 at the modlist page.
Here's a look at the different liveries of the various police forces using the Ford Focus: