Trunk comparison: Opel Astra Wagon vs VW Golf Wagon (Mk5)

Main Differences
Compared to the VW Golf 5, the Opel Astra Sports Tourer stands out mainly in two ways: the trunk opening is +4.3 in (+15%) higher, and the measured trunk depth (loading edge → trunk floor) is +3.5 in (+180%) greater.
Other differences are significantly smaller: with the seats folded down, the Astra is 3.1 in (+5%) longer, with the front seats upright the Golf has 1.2 in (+3%) more length, the Golf's loading edge is 1.2 in (+5%) higher, the narrowest width in the Astra is +0.8 in (+2%), and the opening width is +2.4 in (+6%).
Implications for Usability
The higher opening in the Astra makes loading large or tall items (e.g., furniture parts, boxes, bulky equipment) easier: less tilting when loading, better fit for tall loads, and lower risk of scraping on the driveway.
The significantly greater depth means more usable interior height/volume and allows better stacking as well as placing the cargo further back in the trunk, which improves securing and weight distribution.
The other, smaller differences (<10%) have only minor practical effects: the Astra offers slightly more loading length with folded seats, the Golf slightly more space with the rear seats upright; the somewhat higher loading edge of the Golf makes lifting in slightly more strenuous.