Trunk comparison: BMW 5 Series Touring vs Opel Astra Wagon

Key Differences (>10%)
The BMW 5 Series Touring offers a 9.4 in (14%) longer cargo area with the seats folded down compared to the Opel Astra Wagon.
Conversely, the Opel has a 3.1 in (11%) higher trunk opening and a 0.8 in (100%) greater depth between the loading edge and the trunk floor. Additionally, the loading edge of the BMW is 2.8 in (12%) higher above the road surface than that of the Opel.
Implications for Usability
Longer loading surface (BMW): Due to the significantly greater length with the seats folded down, the BMW is better suited for long items (e.g., slats, skis, long furniture parts) or when larger cargo lengths are regularly needed.
Higher trunk opening & greater depth (Opel): The higher opening and greater depth provide more vertical space when loading and unloading large or bulky items (boxes, suitcases, bulky household appliances). This makes it easier to store tall cargo and offers more usable interior height overall.
Higher loading edge (BMW): The loading edge of the BMW, which is 2.8 in higher, makes lifting heavy items into the trunk more difficult and makes sliding items in from the ground somewhat less practical.
The Opel, with its lower loading edge, is easier on the body when loading and unloading and facilitates loading with wheeled transport aids.
Side note on smaller differences: Minor deviations such as a few centimeters in width at the narrowest point or in the opening width are usually negligible in practice and hardly affect usability.