I know it's a really minor thing, but it would be nice to have the option to have car numbers on liveries.
Whether this comes from having numbers assigned by the league host, chosen by team managers or set by final position at the end of the previous season (with new managers and drivers taking the lowest unused number).
While not a big change it'd be nice to help make teams look more unique rather than all having that same No. 1 on the back of the car.