This file belongs to Aige
https://www.gta5-mods.com/vehicles/2017-ford-gt-add-on-replace-yca-aige

I merely made the Heritage Edition livery, Grey Stitching and interior red parts texture

I have converted the file into an additional file so you can still have an addon Factory/Stock FORD GT file

Drop FordGTHeritage folder to GTAV/Mods/Update/X64/DLCPacks

Go to GTAV/mods/update/update.rpf/common/data
Open DLClist.xml
Add line: 
<Item>dlcpacks:\fordgtheritage\</Item>
