This.
Even as an F1 fan I wouldn’t want the devs taking their time and money to add open wheel cars, even with the motorsport DLC… It just wouldn’t be relevant to the rest of the game…
Although perhaps we could supply engines to various formula series in the Motorsport DLC. So you could design an engine to the regulations, then choose various sponsorship deals: Do you just want to sell the engines to customer teams? or are you going to fund a full factory team? or something in between?(some factory support). It could help boost R&D and provide advertising and prestige bonus to your company.
Gearcity has something like this, although not really that detailed…