I'm looking for modders to test on a modded vehicle

Hi, I'm not a modder, but I'd like to customize my favorite vehicle before GTA 6 comes out. I'm looking for someone who can test adding a school license plate to the Toreador (I'm playing GTA 5 Online Legacy), and see if it's permanently saved when I restart the game or if it disappears.

To explain quickly, I've already asked five different modders to add it, but every time I restart the game, it's gone. So, I need to figure out first if this is a limitation of the game or simply due to the method used to save the plate.

So, thanks to anyone who takes the time to test this.