If I’ve understood it correctly, the reason your driver rating has gone down, even after finishing above where it predicted you to, is because the drivers around you/who beat you etc, had a lesser DR than yourself. So it’s all relative to the particular lobby you’re in. We all know that in the higher ranked lobbies, occasionally there’s only one split. So you may have a few drivers with very low DR in a top split race. Add in to the fact they could have a low DR because they’ve been super unlucky recently; been victims of poor driving, game crashes etc and are actually quicker and faster than you. They beat you, the game sees that a B2 driver has beaten an S1 driver… and even though the description says what it does, it hasn’t taken this into account. So you’ve lost DR because you’ve been beaten by an apparently slower driver.
Because I’ve had the game since launch, with so few players initially, most peoples DR have been overinflated. I’ve had some super lucky races and finished top 5 split 1, where I have no right to be. So there’s that too. Finishing first in split 1 but most of the other drivers have B1/2 DR is not going to increase my DR is it. Now there are more players, things are going to change lots. I mean outside of being super lucky or super unlucky, your DR should stay pretty stable once you reach your limit.
But yes, they really should get rid of all the bumf next to the results. It’s confusing and frustrating people even after they’ve had a good, fun race.