Dealership network?

[MuzzleFlash]

I don't understand how the dealership networks work.

I don't see an option for dealership network levels anywhere except for the creation of a new game. Where do I find it?

bonus question: how do I know where my cars specifically sell?

[Admiral Obvious]

Dealerships are automatically built up as you provide more inventory for them to sell. So, right now, there are no directly purchased dealerships anymore. You should put that same money into marketing instead, so you get more market awareness, and the dealers see more buyers to sell to and expand for.