I was thinking about new special abilities that could be added to further diversify the game and hit on one: Car development.
A driver's technical ability has always been important throughout history, and I think it would be something cool to add to the game, and also probably wouldn't be too hard to implement as it wouldn't really affect the gameplay.
The idea I have is that the "Common" ability gives you 1 extra design point per race; "Rare" gives you 1 extra design point and +5% in research; "Legendary" gives you 1 extra design point and +10% in research.
Obviously that could be re-scaled/balanced if it was decided to implement it, but I just think it would be a cool ability to add