To use these files, open the Menyoo folder located in your Grand Theft Auto V directory, then open the Vehicles folder and place the files inside.

Once you're in game, open Menyoo, go to vehicles options, vehicle spawner, saved Vehicles, and spawn whichever vehicle you want.

As I mentioned in the description, the original GTA V vehicles have limited customization options, so I had to make a few compromises. For example, Letty's Silvia should have a single exhaust on the left side, but the Remus has a smaller exhaust on the right. There are many other examples like this.
As for the Firebolt ASP, I can no longer find the original file for the version with the smaller wheels and front license plate.

If you're looking for a more accurate version of the Jester and the Kanjo, you can download the additional files on gtav mods. I also recommend downloading my second file, which includes the variant versions.

Shal custom's kanjo : https://www.gta5-mods.com/vehicles/kanjo-sj-new-bodyparts-add-on-fivem
NorthwindJME's Jester classic : https://www.gta5-mods.com/vehicles/dinka-jester


Thank you!