It was two trucks that passed, but its on a 2 lane road (1 lane each direction). A tacoma, and something full sized behind them. But neither were muddy/hauling anything. Plus, if anything did break off/fall out of/get thrown by the trucks, it would have to have taken quite the lateral burst of acceleration to bust a window like that.
I first thought it was a rock strike... but I'm pretty certain it was more likely a BB gun or something similar. But, it was loud (similar to rock strike on a windshield, but... like 8in from my head, and the whole thing turned white/frosty looking for a second).
I also thought maybe temperature differential. But, no HVAC was on, it was like 55f, and the vehicle was parked outside that night, so its not like it had a sudden temp change happening either.
The worst part is the falling glass also scratched up the door when it fell. Alas.
Yeah, the first check was "wait, am I bleeding anywhere???"
And yes, I did check for an exit mark on the other side of the vehicle

(haven't found anything yet).
And thanks for the tips.
I haven't been able to get the Regulator out quite all the way yet, but I did manage to get it out enough to get the shop vac in there. And I've been using a spare target arrow to help reach in there and scrape out any of those last pieces of glass. I've also seriously wondered about hosing it out, just to make sure I get it all (not sure if thats a good idea though???).
I will likely order the glass today. I just really wanted to make sure I could get it all apart the way I thought I could, BEFORE I got the glass. That way I didn't end up buying glass, and then having to have someone come out and replace it

.
I'm familiar with auto repair stuff. I just haven't ever done windows before. And its weird how sometimes despite being similar to something you know, certain things can feel more daunting. So thats sort of how I was approaching this at first.