There have been a lot of suggestions recently regarding criminal factions, but something that I think would be both relatively simple to implement and enhance interactions between players is the ability for official factions to have unique access to one import weapon each.
For instance, Marcello’s could have had access to tommy guns, Zeta’s to tech nines, Clowns to sawed-offs. In my opinion, this would enhance interaction between factions, and it wouldn’t be simply going into your laptop and ordering an import for yourself and your boys.
Balance would be key here, so choosing the weapon a group has access to would have to fall on the faction leaders and staff to make sure people aren’t just choosing compact rifles and heavy snipers - but rather weapons that align with the group’s backstory. This would be especially simple to implement now, given there are only two official factions.