In the Marketplace for Forza Horizon 2, you can purchase several car packs. With the game I purchased, I also received a bunch of different car packs. It shows that they are purchased and installed onto my Xbox One, but how can I access those cars? They currently aren't in my garage... Do I have to then purchase those cars with CR to access them?
Unlike Forza Motorsport 5, You still need to purchase the cars in the carpack with CR (First time is usually free). The Day 1 carpack for example are all cars already purchasable as you play through (for the same price as their boring counterparts), but they have a unique livery on them. Purchased Carpacks may be different. I haven't spent enough time in the carshow to be sure ;)
EDIT: It seems there was server issues at launch and car rewards may not have been given out.
Once the servers are stabilized, we will then get to sending out payouts for loyalty rewards cars, Forza Rewards payouts, etc.