Some car mods are not working in my game

[evicter369]

CAN SOMEONE HELP ME IN THIS CASE. I'VE DOWNLOADED AND USED MANY CAR MODS IN MY GAME.BUT SOME CAR MODS DOESNT SEEM TO WORK WHEN I SPAWN THEM USING SIMPLE TRAINER OR MENYOO IT SHOWS MODEL SPAWNED BUT THERE WILL NOT BE ANYTHING.BUT THIS HAPPENS ONLY FOR A FEW CARS .CAN SOMEONE HELP ME IN THIS CASE