I installed overwatch and it fixed all my problems - the only thing it is reporting doing is deleting cars, so unless its doing other unreported things in the background I think that must be the problem - at least in my case anyway. I hadn't been able to get past week 6 in my game, after loading overwatch I was able to make it well into week 10 (nothing went wrong, thats just as far as I've got so far). I uninstalled overwatch and played the same save game and it broke after 5 sim days - stuck and invisible sims in that same chain reaction way that crinrict describes. I'm also (so far) not experiencing sound lag or those annoying pauses/freezes in the game (where the sound will play and fires flicker etc but the clock and all the sims stop running for anything from a few seconds to a few minutes).
