It seems like this is a common issue.. I was having several issues with my car, these all happened on different days:
1) car wouldn't start. kept trying to start it with 3 minute intervals. was successful after 40 minutes
2) car stopped moving while it was still on. engine turned off, lights on dash were still on.
3) car was shuddering between two rpms on the expressway while on cruise. stopped for ~20 minutes, turned it back on and drove fine at 65mph the rest of the way
4) engine had a low rumble at start and glow plug/engine malfunction light was flashing on and off. didn't drive it.
5) came back three days later to take car to shop, and it wouldn't turn on. got it jumped by tow truck and found that the battery was only 7 months old. Odd!
6) took it to shop, was asked if i had let battery die. when i said yes, they mentioned that there was in issue with the throttle valve and they had to reset that component.
Car drives fine now! We shall see in a few days.
I'm not sure if it's completely the same thing, but it feels like it is, so now i feel like i have more peace knowing that ^ is what probably happened with my car too.