This example visualizes the relationship between fuel efficiency (mpg), horsepower, weight, and country of origin for automobiles from the UCI Machine Learning Repository Auto MPG dataset. It displays a scatter plot where each circle’s position encodes mpg and horsepower, color encodes origin, and size encodes weight. The code uses the Vega-Lite API to build the chart declaratively, with the `vl.markCircle`, `vl.x()`, `vl.y()`, and `vl.color()` methods. It loads CSV data via D3’s `csv` function, registers Vega-Lite components, and renders an interactive SVG with tooltips.