I recently bought a PGM4 unit and started experimenting from day one, performing the strangest ideas. One of the many issues that I had with memory cards was retrieving the password from PGM4 units that had no cards at all, altering mileage, etc. Even though I solved these issues, I still wasn't satisfied. I thought that if it's possible to match a memory card to a PGM4 unit, why not go a bit more advanced and match the PGM to the memory card? So let's assume that I have two PGM4 units with only a single card; why not use it to unlock both? If I have a PGM4 unit with 3 memory cards and a second spare PGM4 unit with 2 cards, why not use all 5 cards on both units? And my assumption was correct; memory card matching is not the only option, but PGM4 matching is also possible. I'm not sure if this was done in the past or if it's helpful, but I was intrigued to try anyway. For example, the PGM4 unit that I bought had no cards at all. But I also have here a second PGM4 uni...