I do not know a fix yet but I have figured out what the cause is (most likely) after lots of lost saves and suffering i can conclude it has something to do with the "eat me" license plate frame. I believe that it happens when you customize your wrap then license as this is what happened to me both times. There may possibly be other causes but that is what seems to have destroyed my save for both of my saves. I hope EA can see this and attempt to address the situation but for now i recommend steering clear of this frame.
@Boxcs This happened to me immediately after unlocking it when I bought the Ford Mustang GT legendary custom pack. I noticed that something was wrong and some of my cars wouldn't change properly (this had been going on for days but this was my first attempt to fix it.) I couldn't apply any new sounds or effects to a few specific cars and sometimes if I managed to do so, it would nuke the wrap and I would have to reapply everything. I left the garage to make sure my car was rebuilt properly (sometimes your driving effects don't save the first time and reset back to default), then I noticed that all of the car sounds were completely silent. I knew something was horribly bugged so I quit the game, cleared my cache, and now my car looks like this (see attachment). I can't load into multiplayer anymore at all, it softlocks on the loading screen.
This is stupid. The game has been out for almost a year now, this should have been fixed before they started on Volume 3.
This has been reported multiple times to the bug report forum, the most recent I could find was this:
