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@Hoarse_Gock The ".meta" and ".ymt" files are not required for the mod to work. The map "dlc.rpf" file provided with this mod is also not required. The main dlc.rpf contains only vehicles and NPCs.
So, if you want the most basic functionality of this mod (spawn the vehicles and NPCs as bodyguards or yourself in-game), you only need to install the main "dlc.rpf".
It's like a meal: the main "dlc.rpf" is the meat, while the map "dlc.rpf", ".meta", and ".ymt" files are the potatoes and salad. The meat alone makes a meal, but the potatoes and salad improve it.
I don't have EUP installed, so any file collisions or issues caused by EUP and my mod clashing are unknown to me, and I cannot help in that regard.

@duckman1236206 The dispatch.meta file is optional. The pedpersonality.ymt, loadouts.meta, weapons.meta, and pickups.meta files are also technically optional—if not installed, the game won't break. However, pedpersonality.ymt and loadouts.meta are necessary for all the dispatch.meta files to work, and weapons.meta and pickups.meta are needed for the Tear Gas Launcher to function (and the one dispatch.meta that utilizes it).

@QuasarStorm1995 No plans right now to create marked cars for EISA and ICD. They are agencies that don't have a uniformed division. EISA and ICD agents use the NOOSE Unmarked Cruiser and NOOSE Unmarked Buffalo. Maybe in the future I'll add an EISA uniformed division dedicated to protecting key infrastructure and energy assets, which will have its own marked patrol car.

@QuasarStorm1995 All of them. No local police respond when you gain a wanted level. There are multiple "dispatch.meta" files, each offering a unique configuration of different agencies in the city and in the countryside. There is a "dispatch.meta" where only the IAA responds, one where FAT, DOA, and US Marshals respond, and one "classic" (NOOSE, FIB, US Marshals).

@GTA5NOOSE2 Sure, just follow the rules defined in the permissions section of the mod, i.e., provide credits and a link to this mod. Is the mod going to be published on gta5-mods?

@kaizzzz Not really, I don't think. The FPS might take a hit by a few frames when you have a wanted level due to there being more cops and more variety amongst cops.

@linhtinh94 You're welcome. Sorry I couldn't help you identify the problem and fix the US Marshal Cruiser.

@linhtinh94 The issue I’ve described is caused by literally one line of code in the “NOOSE” carcols.meta file (<id value="7089"/> under ‘NLETP - old’). The issue with the audio and sirens you described is caused by something else.

Answers to some of your questions:
No, you don’t have to install the “NOOSE Expanded Pack".
If you have both mods installed, which dispatch.meta to use is “dealer’s choice".
I mean, it is technically possible for you to use a common file. Yes, you can cut and paste content from the “NOOSE” carcols.meta into the “WSE:Feds” carcols.meta, but that would probably cause a heap other problems. I don’t recommend doing that.
If you wish to install "NOOSE Expanded Pack", you can use the method I've described to stop this minor bug from ever happening by immediately fixing it. Again, from what I can tell, you are currently not experiencing this bug but rather some other problem regarding the US Marshal Cruiser.

Questions so I can try to zero in on your problem:
Are the issues you have just audio (no engine or siren sounds), or are they both audio and siren lights (lightbar)?
Have you installed any mods that might alter vanilla files related to The Chop Shop Update? (the US Marshal Cruiser is the police5 vehicle from that mod)
Are you running the latest version of GTAV?

@linhtinh94 If you are only using “WSE: Federal Enforcement” (and don’t have the “NOOSE Expanded Pack” installed), then the issues you are having with the US Marshal Cruiser are on your end. I’ve even downloaded the current public version and tested it—the US Marshal Cruiser works as it should. I’ve told you before that when I test mods before release, I only have them installed to see if everything is running as it should, with no bugs caused by multiple mods conflicting.

Due to the nature of how I test mods before release, and a small oversight in noting which siren IDs are used/free, the siren ID bug flew under the radar. However, the siren ID bug isn’t causing the issues you’ve described since you don’t have the “NOOSE Expanded Pack” installed. Since it’s a minor bug, I won’t be releasing an emergency update; it will be fixed in a regular future update.

It can easily be fixed by doing one of the following:

a) In the NOOSE Expanded Pack/common/data/carcols.meta file, comment out everything under the “7089” siren ID section.

b) In the WSE: Federal Enforcement/common/data/carcols.meta file, change the “7089” siren ID to something else that won’t cause a conflict with any other code. Then, in the WSE: Federal Enforcement/common/data/carvariations.meta file, change the sirenSettings value=“7089” under “usmarshcruiser” to the same value you’ve used in the carcols.meta file.

@linhtinh94 The bug I've described only appears if you have "NOOSE Expanded Pack" and "WSE: Federal Enforcement" installed.
I'll implement a fix for the siren ID bug with either the next "NOOSE Expanded Pack" update or the next "WSE: Federal Enforcement" update.
I've already mentioned that the US Marshal Cruiser worked fine (audio and siren lights) when I tested it before I released the mod.
The issues you are having with it (unless you have both "NOOSE Expanded Pack" and "WSE: Federal Enforcement" installed, which only causes the siren lights to glitch out (no audio issue)) are caused by something else.