i have the same problem except i have the cars in 64e.rpf, it only spawned 1 CAR and the others just idk dissapeared, i posted something about it or similar too, ill keep you updated if you want to.
guys please help i wanted to load in a pack, but only 1 of them managed to work and the others had different models when i opened their files in open iv, but in game they still had the old model, is there a reason why?
and yes i replaced ALL police cars but only 1 made it in, for example only police.yft loaded in the custom car, the others stayed same.