I have a good idea. There is a load of money that only keeps on growing after players settle. So a feature can be added where a player can purchase a facility in the HQ after reaching a high level(Developers can chose what lvl) after which you can allocate a certain amount of money into making the next year's engine. It is also possible to do that by making 'departments' for making things that are purchased from suppliers. I believe this should not be for rookies as it will make the game more complex for them so I think it should be available after like lvl 10 to 15 where players get a good hold of the game.
This idea does seem to create a bigger devide between richer and poorer teams.
The only way that I would see something like this working is if you had a rolling system where the more money you put into development, the less the overall effect. And it should be implemented from rookie up, with an effective reduction in effectiveness, the higher the level you are. That would, then even out the playing field in general.
The real question from that being, do we really want to make the game that easy for everybody?