LawDawg

You could try to get the original models but you would just have a blank base model and a bunch of parts, not the mod that you have downloaded. The author of the mods you are using got the base model from somewhere and added parts to it, he didn't create any of the parts from scratch (I don't think at least by quickly skimming the credits). Most of the time these parts have stipulations that they must only be used on locked models meaning he can't provide you an unlocked version.
 
I'm not familiar enough with modeling to know how to actually fix LOD issues but I'm guessing whoever ported the original model from Forza didn't set LODs up. Or possibly since it's a lighting issue the LOD issue is with the light bar. Regardless you would need access to these models and knowledge of modeling software to fix it.

It isn't a data file issue, it's a model file issue. Without access to the unlocked model it can't be fixed from an end-user standpoint. 

I do not believe there is a way to have both. The charger should have L0-L3 mapped.
 The fix I provided the first time is the only way I know of how to fix the floating lights other than having all LOD’s mapped.
 
I apologize if that’s not the answer you’re looking for.

I've spent some time messing with it, with both replace and addon, and I cannot seem to find a fix for it (using what I know could have fixed it). It appears to be with the model itself, but I am no car dev and have no idea what the specific issue is, nor can I find anything online that tells me otherwise.
 
I'd suggest, if this is something that bothers you, to try another replacement pack for the time being.

Yeah i've got the same problem at the moment i've moved the ELS around to see if it helps but can't get it working

If you're just trying to edit it within the vehshare.ytd file then you can do it pretty easily with LML. You don't have to find the actual location of the file, just plop your vehshare.ytd file in a folder and create an install.xml with this:
 
<FileReplacement>vehshare.ytd</FileReplacement>  

Thank you sir. I actually realized that there is a much more expedient and time saving alternative which merely entails selecting the SA exempt plate when in the garage. I appreciate you taking the time to respond. 
Thank you sir for the reply. I managed to found a much more expedient workaround by merely selecting the SA exempt plates in the vehicle options menu when in the garage before I roll out on patrol. I appreciate you taking the time to come in here and respond to me. 

In Grand Theft Auto V/Mods/64e.rpf/levels/gta5/vehicles.rpf there should be a YTD file called vehshare.ytd and in there should be the texture of the Yankton Plate

Hey there,
Most trainers include such functionality. If you haven't installed one already, I would recommend doing so.
 

Thank you for the excellent suggestion; one which I had not actually contemplated. Incidentally, I'm also a huge Naya Rivera fan. In pace requiescat. 

Go into your lspdfr.ini and reduce values of these options: AmbientSpawn.MaxCopsInArea ; AmbientSpawn.MaxSpawnedCopsInArea.