I was having this problem when I first started adding vehicles to GTA V. I backed up my game, and made myself a Mods folder in Open IV as I was told. I would follow instructions precise when adding new vehicles into the game. However when I would get on, and try to spawn one of the new vehicles, almost all of them that spawned were Vanilla, or a vehicle I already had installed. The only one that seems to be working is the "police" car. I can change that one all the time, but the others don't. This is a problem because I try to download all the big/mega packs. If you can help, please respond!

 

Thank you!

Most likely this is due to where you are editing the car files at. For police you can edit this in x64e>levels>gta5>vehichles.rpf. For the rest of the police cars you will need to edit them in update>x64>dlcpacks>patchday9 in order to see any type of change.

 

GTA 5 has a built in patch system where the developers can add a simple patch folder which will override the other files in the base game. This can lead to the issue where a new update is pushed for GTA V in which they update a car you modded and it no longer will appear in the game. To circumven this I suggest you upload all the modded car files you wish to  use in the latest patchday folder (Currently patchday17). If you do this all the cars should show up in game utilizing the correct vehichles.meta file.

I've been modding gta v for years and i am now having this problem even after taking the necessary steps to install the vehicles correctly. Some of them i get and invalid model error or they spawn and look like the developer never finished them when they've worked for me in the past and i know they worked because i would play for hours. Any ideas?