This example shows the highest city MPG vehicles by make, using a sequential bar chart where warmer reds indicate higher MPG values. The chart sorts car makes from lowest to highest MPG, with interactive tooltips displaying exact values on hover. Built with D3 v6, it uses `d3.scaleBand`, `d3.scaleLinear`, and `d3.scaleQuantize` to map data, while `d3.axisBottom` and `d3.axisLeft` render axes. A color legend from the d3-legend library explains the red color scale, and all graphics are drawn as SVG elements with mouseover/mouseout events.