A simple asi plugin for GTA V that removes the restriction when attempting to spawn new dlc cars that R* added in since game build 1.0.617.1. Also adds new cheat codes that will spawn the blocked cars using their display name as the cheat code.
To spawn the cars, open the cheat input textbox (using the ` button on the keyboard). Then type in the name of any of the cars listed in the log file that will be created in the GTA V directory (EnableMPCars.log). The lines should look like this:
[10:32:34] Found affected hash: 0xD7C56D39 - DisplayName = RAPTOR
so you can type "raptor" into the cheat box and the raptor will be spawned.
I know this is a bit of a pain but its the only real way to make this work without having to update each patch and without having it rely on ScriptHookV which always needs updating after a patch.

Once ScriptHookV is updated any trainer that can spawn cars should be able to spawn these without them getting despawned after 5 or so seconds

Installation

Just drop this asi file in your GTA V directory, then make sure you have an asiloader installed(dinput8.dll) This can be acquired from:

• OpenIV - Use the ASI Manager in the tools menu to enable the asi loader
• ScriptHookV

The Visual studio C++ X64 redistributable 2015 is required to run this plugin. This can be installed from Here - make sure you select the vc_redist.X64.exe file on the download page.

ScriptHookV itself isn't required to use this plugin.

Also If you dont want to use the asi loader after a game update due to ScriptHookV throwing an error, you can just use a program like Cheat Engine to manually inject this dll once you have started up the game and the features will work as normal. If injecting manually this asi will still need to be in the same directory as GTA V otherwise a fatal error will be thrown crashing GTA V.

I should also say do not try to use this in GTA:Online, you will most likely get banned. However none of the features would have any effect online anyway(cars arent blocked, cheat controller is unloaded.)

Credits:
drp4lyf