Trunk comparison: Audi A3 Sportback vs Renault Clio

Key Differences (Summary)
The most noticeable differences concern the folded cargo length, trunk depth, and loading edge height. The Audi A3 Sportback offers a longer loading surface with folded seats (+6.7 in / 13%).
The Renault Clio has a significantly larger trunk depth (+24 in / 381%) (measured as the distance from loading edge → trunk floor) and the loading edge of the Audi sits significantly higher above the road (+16.9 in / 179%).
Impact on Usability
Longer loading surface with folded seats (A3 +6.7 in / 13%)
The A3 is better suited for long items (e.g. slats, long boxes, skis) when the rear seats are folded down. With the rear bench upright, the difference is only +2.4 in (8%) and thus hardly noticeable in practice.
Significantly greater trunk depth in the Clio (+24 in / 381%)
The Clio offers more vertical space inside between the loading edge and trunk floor. This is advantageous for tall or bulky cargo and can significantly increase usable volume.
However, a deep loading surface also means that cargo lies further "deep" in the trunk — depending on arrangement, rearranging or removing small items can be somewhat more cumbersome.
Higher loading edge on the A3 (+16.9 in / 179%)
The significantly higher loading edge of the A3 makes lifting heavy items into the trunk more strenuous. The Clio with its lower loading edge is overall more ergonomic and easier to handle when loading heavy loads or bulky furniture.
Smaller differences (under 10%) such as a slightly greater trunk opening height (+1.2 in on the A3), as well as slightly greater widths at the narrowest point and the opening on the Clio (+2–1.2 in) are marginal in practice and rarely affect everyday usability.
Conclusion
For long, flat cargo, the A3 Sportback is the better choice. For heavy, tall, or bulky items, the Renault Clio is more practical and ergonomic for loading due to its deeper loading surface and lower loading edge. Smaller width and height differences usually play only a minor role in everyday life.