The next Forza Motorsport absolutely needs Daily races (one per each car class) and weekly Championships with rewards (example: Dirt Rally 2.0, Asphalt 9)
Once the Career mode is completed you end up with tons of cars but no more races to do with them unless you go into Multiplayer.
Give us more events to do with our favorite Cars.
As rewards, you can give visual upgrade parts or logos for use in livery editor, credits, new cars, etc.