For those of you having issues where you can't see the Ferrari drivatar after the race against the chopper.
There are 2 Fixes going around:
1) Delete your Save folder
This will mean you will have to start again but should fix the issue (it worked for me at least)
2) This one is a little weird but the source is reliable Download this archive from this link: https://drive.google.com/open?id=1ObMypz5AkC8XJ45U4SmvKEfTNjKDGcJ0
and follow these instructions
Unzip the folder do
EDIT: If you encounter this error below. Copy the appmanifest.xml from the AppFiles folder in the Forza directory to the Uninstall directory. The script cannot find the file as it does not exist in the searched location.