Ok, I think the challenge is going to have major issues in its current state, so here’s what I suggest:
Set it up similar to the previous generations challenge with one major change. Instead of 1 car, companies can submit 1 car per category in as many categories as they want (could be just 1 total or 8 etc.). Each company gets an average score of their cars and a cumulative score of all of their cars instead of giving people 0s for not hitting markets they don’t want to build for.
What this does is not pressure people to stretch their lore into something they don’t want it to be and also allows people to relax when irl stuff comes up and they can’t chug out enough cars in a given time period. It also sets up two goals for people to aim for: quantity and/or quality (as opposed to who has the most free time).
A few weeks sounds like a much better window than 10-14 days. That gives you more time for reviews too.