A D3.js bubble chart displays the correlation between average horsepower and average torque for different car makes, with bubble size and color encoding highway MPG. The visualization uses `d3.scaleLinear` for positional and size mappings, and `d3.scaleOrdinal` with `d3.interpolateTurbo` for categorical coloring. Hover interactions trigger tooltip handlers that show the car make. The chart is rendered as SVG and includes a legend for both bubble size and color categories.