Installion of this add-on:

1. Copy and paste the folder "shelbymr5" into folder mods/update/x64/dlcpacks;

2. start OpenIV and open mods/update/update.rpf. Browse to folder /common/data;

3. extract files 'dlclist.xml' and 'extratitleupdatedata.meta' to your desktop;

4. add a line <Item>dlcpacks:\shelbymr5\</Item> to the list of dlcpacks in the dlclist.xml;

5. add entry below at the bottom of extratitleupdatedata.meta. If you look you'll see similar lines.
Add this as the last one;

<Item type="SExtraTitleUpdateMount">
<deviceName>dlc_shelbymr5:/</deviceName>
<path>update:/dlc_patch/shelbymr5/</path>
</Item>

6. click the edit-button in OpenIV and drag the edited 'dlclist.xml' and 'extratitleupdatedata.meta' back to mods/update/update.rpf folder /common/data;

To spawn the car type "shelbymr5" in a trainer of your choice