Trunk comparison: Opel Grandland vs VW Golf Wagon

Key Differences (>10%)
The VW Golf Wagon offers a larger cargo area: With the seats folded down, the trunk is +7.1 in (11%) longer, and with the first row of seats upright, it is even +7.9 in (22%) longer than the Opel Grandland. This means the Opel Grandland lacks longitudinal volume compared to the Golf.
In contrast, the Opel Grandland has a significantly greater trunk depth (loading edge to trunk floor): +2 in (45%) compared to the Golf. Additionally, the loading edge of the Grandland is considerably higher above the road: +6.7 in (28%).
Impact on Usability
More length in the Golf Wagon practically means better suitability for long items (e.g., roof rack parts, long boxes, skis) and overall more usable cargo volume — both with folded and upright seats. For regular transport of longer or bulky items, the Golf is therefore the more practical choice.
The higher loading edge of the Opel Grandland makes loading and unloading heavy items more strenuous; this especially applies to boxes or furniture that need to be lifted.
The greater trunk depth means the cargo space is "deeper": This creates more vertical clearance inside the trunk and can better recess small items or allow for more storage volume under a flat loading edge, but it worsens the lateral sliding in of long items and makes pulling them out more difficult when the loading edge is high.
In summary: Those who frequently transport long or bulky loads and prefer a lower, more accessible loading surface are better served by the VW Golf Wagon. Those who benefit from a deeper trunk floor (more recess/storage space) and can live with a higher loading edge will find a suitable solution in the Opel Grandland.