There could always be a MotoGP style split class.
Factory:
main teams backed by an engine manufacturer:
- Mercedes
- Ferrari
- Red Bull-Renault (and maybe STR-Renault)
- McLaren-Honda
These teams have totally frozen engine development and 4 engines and 5 gearboxes per season.
Open:
all other teams
These teams have a choice of chassis constructor (who can themselves be in the open class) and engine supplier. Triple engine and gearbox allowance, and free development of engine and aero kit. Chassis constructors can oblige a team to give a new aero piece for examination and the factory teams can take up to 4 engines and 5 gearboxes total from any team they supply for examination (which can be placed in the factory car, but go against their allowance).
All constructors (engine and chassis) must supply parts identical to those used by the works team or face Championship exclusion.
The constructors (and its prize money) will be split between teams' and constructors' championships. The F1 Teams World Championship is based on points per team, while the Constructors will be based on the two highest finishing cars of a given chassis-engine combination in each race (so that the championship isn't decided by the most used chassis).