Zeusz13

And if you really want a custom agency, then copy Agency_lspd, paste is somewhere else, change the name of the file, and paste is back, then do exactly as I told you above in the first paragraph, along with changing the scriptname. So if you change the scriptname to <scriptname>nypd</scriptname> then you have created a custom agency. You now have to add that agencies scriptnames into the backup.xml, duty_selection.xml, and stations.xml in lspdfr>data.
 
If you add nypd to the lossantoscity region in the backup.xml, then those units will patrol and respond in that region. 
If you wanna know what region that covers you look in the regions.xml
And if those zones are jibberish to you then refer to this fileZones reference.txt
And if you wanna know where those zones are here you go

If you decide to move zones around make sure you delete it from where you moved it from or its going to be messy.
 
Duty_selection.xml is what you see when at a station going on duty, choosing cars and outfits. if the agency (nypd) is in <Peds> then you will see the option to choose from that agency when going on duty. If its in <vehicles> then diddo. the vehicle desciptions is what the game will name the cars as when choosing. name then whatever, just make sure whatever vehicle you add to the agency of nypd has a description here. Specify which agency the vehicle is for by placing the scriptname in agencyref.

 
The stations file determines which peds and vehicles will be parked and standing around the stations, add the scriptname to wherever should be placed.
 
Then you have done it. Now if you want custom NYPD outfits then you need to install them. Find out where they are in the closet at your apartment and write down the numbers of the locations. example is ID 3 is shirts, drawable is what shirt "54" and the texture of the shirt "2". Then copy outfits_lspd, copy it, change the name, paste it back, trim it down a bit Im sure you wont have 10 outfits. Paste the numbers in that you wrote down and change the names up.

 
Sciptname is what you will refer to in the agency file

 
 

I had the same issue, so I decided to look into the culprit (notice it looks like the Party Bus lights?). When I looked into the carcols.meta for both the pack and the After Hours DLC, I noticed a simple issue: The Party Bus's Siren ID is 15 like the Tahoe and the Charger. To fix this, you have to fix the Captain14 stuff, as Rockstar won't be editing their numbers for the modding community- unfortunately. You can use any numbers you'd like that don't correspond to an existing config (remember, we're adding a siren flash pattern, not replacing, and when Captain14 made this stuff, ID 15 was available for adding to the list of patterns, hence why the FBI pack is still working, as its numbers are something like 29 and 31 I think). Feel free to repeat this process when fixing/future-proofing the Captain14_FBI pack (just don't use the numbers you used to fix this car pack or you'll run into the issue of Captain14_Sheriff patterns on the FBI cars or vice-versa)
Steps:
-Open Captain14_Sheriff's carcols.meta file
-At the top of the document, change 15 as in <id value="15"/> to "69" or something not in use by Rockstar (use what's below if you want- it's at the very top of the file). This will fix the Charger and the Tahoe.
<Sirens>
      <Item>
          <id value="69"/> <!--Custom siren settings-->
          <name>custom siren</name>
-I would go ahead for the sake of future-proofing and change the other custom one "17" to something like "100" or something not in use by Rockstar (search for: id value="17" , then replace it with what's below if you want)
<Item>
          <id value="100"/> <!--Custom siren settings vic-->
          <name>custom siren 2</name>
-Once you have reassigned the Captain14 light pattern ID numbers, open up Captain14_Sheriff's carvariations.meta file
-For the Tahoe and Charger, replace  <sirenSettings value="15" /> with  <sirenSettings value="69" /> (or whichever number you put as the siren pattern for the Tahoe and Charger & isn't 69)
-For the CVPI, replace  <sirenSettings value="17" /> with  <sirenSettings value="100" /> (or whichever number you put for the siren pattern for the CVPI and isn't 100)
-Pray that Rockstar will never add another light pattern and hope that if they do, it won't mess with the FBI pack
-Boot up FiveM or LSPDFR and hand out a ticket to those party bus drivers for screwing up your lights 😜Here's proof of this trick working!

Cheers!
-RacermanXtreme