Races are a good idea but something like a battle event with its localization on map, new players just get lost and lose motivation, we have offerings and daily mission but something more interactive with many people would be a good idea. Like putting some special painting instead of a colored piece you give a pot of paint and the player can color one piece he wants things like this, commemoration events and alike, or crates with premiums. One important thing is that all need to be avaible after event or in a next event so people can have a chance to get it again to motivate them to enter the game even if they quit for some time.