Since early March I have not been able to add any extras to any police vehicles. I have looked almost everywhere online to try to find a solution and even reinstalled LSPDFR, but nothing has changed. When I am selecting a car in the police garage, the car loads fine and the lights will come on, but when I select an extra to appear on the car (like a light bar or ram bar) it appears on the car for only a second and then disappears while the "extra" slot in the selection box is still in the "on" position. I have even tried to add the extras after selecting the car in the garage through the Simple Trainer, but still nothing happens.

I don't reallly know if that's the issue but is it an ELS car ? and do you have ELS installed ? If that's the case then it probably is related to it, since it works with the car extras