k that points even more toward it probably being related to adding Car Crew Members to a Vehicle that suddenly became invalid. At-least that's my guess at the moment. v18.104.22.168 has more checks within the cycle to see if that is the case and prevent it. If that is the reason it happened it should be less likely to be able to happen now. It's still possible due to timing but if it at-least reduces it then we're on the right track.
Also let me know what you think of the car selector. That was such a good suggestion from you. I'm enjoying it myself
I'm going to go ahead and add a few more models to that list and alphabetize them to make it a bit easier to find the desired model.