This example visualizes the relationship between fuel efficiency, horsepower, weight, and country of origin for classic automobiles, using a scatter plot where each car is a circle. The visualization is built with the Vega-Lite API, which constructs a specification rendered by Vega, with data fetched from the UCI Machine Learning Repository’s Auto MPG dataset via D3’s `csv` function. The API encodes the x-axis as miles per gallon, the y-axis as horsepower, color by origin, and size by weight, while a tooltip displays each car’s name. The chart fills the browser window and uses custom axis labels and colors for improved readability.