A 100% save game in Forza Horizon 5 means that you have completed all the achievements, collected all the cars, and explored the entire game world. Achieving a 100% save game requires dedication, skill, and a lot of gameplay.
If any of these don't look right, the swap may not have worked. forza horizon 5 100 save game microsoft store link
All accolades, stories, and festivals finished. A 100% save game in Forza Horizon 5
Overwrite the original file with your newly renamed 100% save file. Step 4: Syncing with the Xbox Network collected all the cars