Add Circuit races with the tire wear feature like in the motorsports playlist. Sprint race and endurance race separate options would be nice. Sprint would work as 3-5 laps around the track, and Endurance would have 6-9 laps. To really go above and beyond, add a leaderboard for points gained in races and at the end of every week or month you get a reward.
Grand Race and Demolition Derby get old, and a lot of the features in game that can be great addition to multiplayer are just ignored (For example the Rally Race in the red-bull playlist, motocross, and Circuit Racing like in the motorsports playlist). What’s the point of race tracks in an online game if there’s no online races using them?