This example renders a scatter plot of automobile performance data from the UCI Auto MPG dataset, showing miles per gallon against horsepower. Each circle is colored by country of origin and sized according to vehicle weight, with tooltips displaying model names. The visualization is built using the vegalite-api, which composes Vega-Lite specifications programmatically in JavaScript, then renders them through Vega with an SVG view. Data loading uses `d3.csv` from D3 v5, while vega-tooltip provides interactive hover details.