(Note: I can also suggest related search terms to continue research.)
If you are looking for free files, these community-driven and open-source platforms are the safest starting points: Platform Name Best Suited For File Types Available Access Model Older GM, Ford, and BMW Binaries (.bin) and Definition files (.xdf) Completely Free RomRaider Forum Subaru, Mitsubishi, BMW MS41/42/43 Stock ROMs, community base maps Free / Account Required NefMot Audi and VW (Bosch ME7 ECUs) Original files, Stage 1 community definitions Free Open-Source ECUConnections European Diesel & Petrol (Bosch, Siemens) Chiptuning guides, original binaries, user mods Registration / Contribution Critical Risks of Using Free Tuning Files ecu tuning files database free
Top 10 ECU Tuning Software Programs for Professionals - Reynlab (Note: I can also suggest related search terms