The first one was a tie down strap (buckle) I saw intact
in the bike lane. It stayed there and passing it by every day for maybe a week I saw the buckle break apart, attesting to how cars veer off their path into ours all the time. Finally stopped to pick up the pieces and throw the belt off to the side. Second one is disconcerting as there's reports of parked car windows getting shot with bb / pellet guns. And if you hit that one on a night ride your front tire could slide out from under you.
