My suggestion is that there should be a Trophy Room, maybe instead of the Achievements section, it should be visible to anyone. It could have "stock" trophies, taken from a selection as supplied by the game, or custom ones, uploaded by the league host.
Trophies would be for just the top 3 in each division at the end of the season, not for every race, to avoid the Trophy Room becoming too full. This gives a type of reward to the top 3 managers in each division (I noticed that the rewards suggestion was rejected) and gives them something to show off, a little like the teams in F1 showing their WDCs and WCCs on the sides of their motor homes. Yes, it's a form of bragging but so what? It's there anyway, in the stats where it says number of championships won. The problem with that is that you could win championships in an uncompetitive league and no one would know, with the Trophy Room idea, you could have different sections for different leagues with the league name over the door, that way, if you were so inclined, you could check out the leagues that certain championships were won and decide if they were competitive or not.
There are all sorts of possibilities with a Trophy Room