This interactive scatterplot uses the Vega-Lite API to visualize the relationship between engine displacement and horsepower in the auto-mpg dataset, with tooltips revealing vehicle names. The code configures a filled line mark with low opacity to create a density-like overlay effect, styled with custom axis and label formatting for readability. It loads data via d3.csv, registers Vega, Vega-Lite, and Vega-Tooltip, and renders an SVG chart that fits the full viewport.