Idea of Convertible Icon
There’s a rectangle with two circles on the bottom- one on the left and one on the right to symbolize wheels. On the top of the rectangle there is a slanted line where the window would be on a car and a small triangle symbolizing the car seats.
This page contains the Convertible vector icon, as well as variations of this icon in different visual styles, and related icons. All icons are in the flat vector style, however, differ by the line thickness, fill, and corner radius.