Tried bribing Unione Corse, still a slow increase. Now I'm stuck at 0.8. I can't buy the ID because I am not friendly enough. What do I do? I have Unione Corse iff.
Once you have achieved maximum friendliness with the Brigands, use the "/droprep" command to lower the rep of your current IFF and apply the next reputation available.
This will require you to become friendlier with the Brigands first, though. Shooting Gallic Corporate NPCs should work for this.
Your current IFF will be dropped and the next highest will be assigned after you relog - assuming it's high enough for you to get the IFF in the first place. Keep doing this until you get the desired IFF.
As Echo said, shoot NPCs to bring it up if you are just short.