Fantasticer

So i was wondering wether you can replace dlc police cars that come from gta online such as polcaracara. Now i tried that the replacement was fine but the issue is that the liveries did not properly load, for example i imported an lapd durango as a replacement for polcaracara (4x4 suv) and it did not come as expected. Els and driving worked fine but the skin wasnt the one i needed. And also when i replaced stainer with a crown vic it was uncontrollable the car flipped on every turn. I wanted to ask wether replacing dlc cars is possible or not