This example visualizes the Auto MPG dataset from the UCI Machine Learning Repository, plotting each car model as a circle positioned by fuel efficiency (mpg) and horsepower, with color encoding the country of origin and size representing vehicle weight. The visualization is constructed programmatically using the Vega-Lite API, which registers Vega and Vega-Lite libraries to render SVG. Data is fetched asynchronously via d3.csv, and the tooltip feature from Vega-Tooltip is attached to show car names when hovering.