Forza Motorsport 4 Save Modding

Hello, I recently booted up my old Xbox 360 and decided to mess around with Forza Motorsport 4. I didn’t have any credits (less than 250k) and wanted to modify some of the more expensive cars. So I downloaded Horizon and paid for a month of premium… But I’m worried about the tamper protection in Forza 4, I’ve heard about accounts lost after using horizon to edit the save game… Is this still something I need to worry about? I don’t want to lose the save file and I’ve made a backup, but I wanted to mod in around 100 million… Will this set it off? Thanks in advance, I’m typing on mobile so sorry about any typos.