A single blue line traces automobile sales from 1999 to 2013, with the year on a time-scaled x-axis and sales on a linear y-axis. The chart uses D3 v5's `scaleTime`, `scaleLinear`, `axisBottom`, `axisLeft`, and `line` to construct the SVG rendering. Data is loaded as CSV from a GitHub gist, with parsed year and sales values. The visualization includes labeled axes, a title, and a grid of tick marks.