FYI,
A couple of days ago I noticed a slight knocking/metallic scraping noise coming from the front of my car. I could also feel it through the floor and steering wheel. It seemed to get progressively worse each day. This noise would only occur when decelerating/coasting and only in a straight line. Its frequency would also depend on how fast I was going. Otherwise, when accelerating or turning it wasn't there. Sometimes starting from a full stop would produce a clunk which sounded like something fell into place.
At first I thought it was either the driveshaft, CV's, or even an engine mount, but after MUCH googling I ran across my exact scenario. Turns out all the wheel bolts on my left front wheel were loose!! Two of them were so loose I could use my fingers to easily turn them. Why they were that loose I don't know. Could've been vandalism, or maybe gradual loosening since I got my brakes replaced a month ago.
I'm just posting this for future reference for anyone that may encounter this issue.