A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A seamless pattern formed from miutopia mug remixes on a tablecloth.
Source Firkin
From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
A seamless texture of an abstract wall colored in shades of light orange brown.
Source V. Hartikainen
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Groovy Concentric Background No Black
Source GDJ
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin