DLC/MP vehicles despawning

[MRDotted]

So I've been having this problem ever since the last update. Whenever I attempt to spawn a DLC/MP car (Such as the Gauntlet Hellfire), they appear for a few seconds and then disappear.

This happens with the vehicles from the Diamond Casino and Resort DLC. I've tried using mods that allow MP vehicles to be spawned in SP but they only crash my game. Is there any way to prevent this from happening?

[Dock-6]

Try using either

https://www.gta5-mods.com/scripts/simple-trainer-for-gtav#description_tab

or

https://www.gta5-mods.com/scripts/add-on-vehicle-spawner

whichever one suits your needs. They can both co-exist if you want.

[MRDotted]

@Dock-6 sorry for the late response.

I am currently using Simple Trainer, and whenever I spawn vehicles from it they despawn. Same thing happens with the addon vehicle spawner.