This is the most critical part of this review: You cannot use a save editor online.
For specific Forza titles, community members have created editors that handle the specific database IDs for cars and upgrades. forza horizon 1 save editor xbox 360
This paper examines the development, functionality, legal and ethical considerations, and community impact of save editors for Forza Horizon (2012) on the Xbox 360. It explains how save editors interact with console save files, outlines typical features (inventory/credits/vehicle editing), discusses technical methods used to locate and modify game data, and analyzes risks including account bans, data corruption, and copyright/terms-of-service violations. The paper concludes with best-practice recommendations for researchers and hobbyists exploring game save modification. This is the most critical part of this
Here is where the magic happens. The interface is usually tab-based: Here is where the magic happens
Crucial Tip: Do not give yourself "duplicate" cars of ones you already own if the editor doesn't support duplicate removal. It can cause visual glitches in the garage.