A black push-in clip.
Mazda lists BC1D-56-145 as a retainer.
Sizes: 8mm hole, 20mm head.
OEM numbers: Mazda BC1D-56-145.
Fits Mazda.
Model years from the car maker's parts catalogue (US-market years; check your vehicle)
Mazda 2 2011-2014
Mazda 3 2004-2013
Mazda 5 2006-2010, 2012-2015
Mazda 6 2003-2013
Mazda 626 1998-2002
Mazda CX-5 2013-2016
Mazda CX-7 2007-2012
Mazda CX-9 2007-2012
Mazda Miata 1999-2005
Mazda MPV 2000-2006
Details
Mazda part number: BC1D-56-145, BC1D56145
Mazda CX-5 Fender liner clip