If you're trying to add this in the latest update changed how you install it, instead of putting it in x64e.rpf not you need to put it here - Grand Theft Auto V\mods\update\x64\dlcpacks\patchday10ng\dlc.rpf\x64\levels\gta5\vehicles.rpf
all the rest of the handling mods and everything else go in the same place, just the model is moved.
5mods on Discord
If you're trying to add this in the latest update changed how you install it, instead of putting it in x64e.rpf not you need to put it here - Grand Theft Auto V\mods\update\x64\dlcpacks\patchday10ng\dlc.rpf\x64\levels\gta5\vehicles.rpf
all the rest of the handling mods and everything else go in the same place, just the model is moved.