"Nico
Even with only 1 race per week it's impossible I think.
You only gain 1% for each development so you need 99 days for developing 1 part to 100%.
We have 17 races. 17 races with 7 days a week we have 119 days to develop.
So there is a possibility to get some parts to 100% but I don't think you can develop the whole car to 100% because you need around 60 designers per part.
Designs are scaled to how often you race, so if you race once a week it takes several times longer than in a daily league. The minimum time is still the same, but it requires a lot more designers to be as fast in a weekly league.