A while ago experimenting with the INI files I found this options.ini in SteamLibrary\SteamApps\common\assettocorsa\system\cfg
[OPTIONS]
AUTOFLIP_RECOVERY=1
PROVIEW_MODE=0
RENDER_SPLINE=0
DISABLE_SHOW_MODE=0
If PROVIEW_MODE=1 then there were no in car cockpits which I found odd but so I set it back to 1. This shouldn't have been changed in the update but maybe check this file and make sure its set to PROVIEW_MODE=0