A reusable D3 scatter plot cycles through four numeric car-sales variables—mileage, engine size, year of manufacture, and price—on the x-axis while price stays on the y-axis, updating every 2.5 seconds with an animated transition. Built using `d3.scaleLinear`, `d3.axisLeft`, and `d3.axisBottom`, it renders SVG circles from a Kaggle CSV and re-invokes the chart function to swap axes. The code demonstrates a modular `scatterPlot` factory pattern with setter methods for width, height, data, and accessors.