Whitechocalate587

I had this problem too couple months back . Go to your directory of GTA IV and delete AdvancedHook.Init . The ELSv8 should work now.

Install everything he said but BEFORE you install LCPD:FR, start GTA and make sure it works and that your computer will run it. Then after you've tested it and know the game runs on your machine then you can make a backup of the GTA IV folder and then install LCPD:FR and whatever else you want. I say test the game prior to installing LCPD:FR because if the game doesn't run after FR is installed then you know where your issue is. Making a backup will take a few minutes but it will save you a lot of time when you don't have to re-install the game if you screw something up. Worry about car mods, script mods, player mods, etc after you have everything running smoothly and test the game after installing something. Its hard to troubleshoot when you install 15 mods at once and the game doesn't work

You can only use different textures for police cars models. You have Police (Vapid Cruiser), Police2 (Police Patrol in game), Noose Cruiser, Noose patriot, FBI. All those cars have 4 liveries (used to have, at least, they say you can have more now). using '?do=embed' frameborder='0' data-embedContent>> you can assign a different livery to different city area.
 
Example from my game:
 
Police Cruiser:
Livery 1 LCPD, assigned to Algonquin
Livery 2 Northern Gardens police, assigned to Bohan
Livery 3 LCPD HWY, assigned to highways. 
Livery 4 Alderney State police, assigned to Alderney.
 
Same with other cars.
 
So basically you download a car model you like, when you find textures which suit the model (I got mine from several different car mods), and then apply to each area.