I think Forza 5 and Ryse also did this. I had to pay 60 dollars for both, but I will not make that mistake again.
Ryse has them for multiplayer, which I don't really mind. It's annoying when it starts branching over to single player, which is what this looks like. I don't even see why this series needs microtransactions; what grinding would be required to get one of these vehicles?