Here's a strange one. I have an infestation of some kind of buggy beetle. How do I get rid of them?

I left all the windows open for about 3-4 hours one nice afternoon 2 years ago. Apparently during this brief window, some of these tiny black beetle bugs took refuge in the 4runner. I vacuumed all of them and for the next few weeks hand picked the stragglers. Didn't see any over the winter. I get in the truck yesterday only to find these little f-ers are back in force! They're mostly in the driver footwell, with some on the passenger footwell and 2 or 5 in the rear.

Clearly they've set up a breeding area not visible to the human eye.

IMG_20190516_084423.jpg - Google Drive