This is just a heads-up for people coming from the old iGP who are confused about suppliers. I've seen a couple of comments/posts now with people saying that their suppliers were not transferred from the old iGP and quickly switching back to what they understood to be the "best" suppliers from the old game.
I'm here to tell you that it isn't necessary anymore, because the best supplier for your team is the one which boosts any attribute you want to increase. The best supplier will be different for every single team based on what you want to emphasise in the car design. Keep an eye on which attribute you see getting a bonus with each supplier when choosing one, and don't just go by knowledge from the old game because that is irrelevant under the new system.
It's one of the intended changes from the old game, because it was too easy to just have one supplier that everyone knew was the best and it created no variety or choices. The new system presents choices and multiple options.