This bubble chart visualizes the correlation between average horsepower, torque, and highway MPG across 31 car makes, with each bubble’s size encoding highway MPG and its color representing the manufacturer. Built with D3 v7, the SVG visualization uses `d3.scaleLinear` for axes and bubble sizing, and `d3.scaleOrdinal` for color mapping. Hovering over a bubble triggers a custom tooltip via `mouseover`, `mousemove`, and `mouseleave` events, while a legend shows MPG values and make colors.