I often render down my replays for the viewing benefit of some friends who say they find it oddly satisfying to watch this gameplay. What I noticed today is that as of the Spring season, the replays (and this extends to both the ghost during gameplay and the replay editor) lack the cars' spoilers. They just stay folded down throughout the race.This first occurred on the 29th of March, after the first update to prepare for the Spring season.
Old replays are also affected, which suggests this is an issue with the reading of the replays rather than the writing.
Edit: Also appears to affect other pieces of car rigging, air brakes are likewise AWOL.