This example shows the distribution of car brands in a dataset as a pie chart, with each slice labeled by brand name and its percentage of the total. The visualization loads data from a remote CSV file using `d3.csv` with `d3.autoType`, then aggregates counts per brand via `d3.rollups`. It computes slice geometry with `d3.pie` and renders the arcs using `d3.arc`, applying a categorical color scale with `d3.scaleOrdinal` and `d3.schemeTableau10`. A manual legend lists the brands, using SVG groups and rectangles.