In the interest of promoting vehicle combat -use- I would suggest that more red factions such as gangs and syndicates have their own garages. These wouldn't necessarily be puppet-able garages, but more a place that a gang or faction could 'hire' a PC mech to come and fix their equipment for them (maybe leaning on the rental system used with other garages elsewhere). This would give these factions a bit of privacy to set up a more long term project to spring on their enemies, and also provide an outlet outside of coded 'jobs' for some auto/aero tech shenanigans.