TrooperSadowski

Additionaly to Lennyy's advice you have to change in lspdfr.ini string: Main.WorkaroundDLCVehicles = true, set to false.

You can do one of two things. Either replace the gauntlet with another vehicle, for example, a hellcat, or remove/replace the entry with the update.
 
For replacing the car, rename the car files you want to replace to polgauntlet and place it in the same location you install the rest of your police vehicles. Do not remove tags such as _hi or +hi as that can mess with the model and texture files of the car.
 
If you just want to remove it as its entirety without seeing it as a different vehicle as I mentioned above, follow the below instructions;
Go to the path Grand Theft Auto V\lspdfr\data and locate agency.xml Open via a notepad or XML code reader. If you need it, I would recommend Kate XML Editor. (I personally use this) Search for "polgauntlet" via CTRL+F  Either replace this with another vehicle slot (Ex: police2, sheriff2) or remove the entirety of the entry line. Line will look something like this: <Vehicle is_dlc="true" use_modkit_liveries="true" livery_multi="4,16,19">polgauntlet</Vehicle>  
Since this forum became a little more popular than I really anticipated, those who come here in the future looking to remove the new Police Crown Victora released with the chop shop DLC, the same method applies, except it is named "police5", so search for that instead.