What do British call these
http://www.seattlefabrics.com/Marine%20Grade%20Snaps.jpg?
I don't think cars use snaps. I can't find the right word. Let me try to describe how they look like.
Like snaps, they are male and female components. When they are connected, they snap or click. However, as far as I know snaps are round which is not what the fasteners look like. The male component is a rectangular hole with some hooks along its lenghts. The female is just the opposite so when it's poperly insterted, they will click. Sorry for the poor description.