Trunk comparison: Audi Q7 vs Mercedes Benz GLC

Key Differences
The Audi Q7 offers significantly more loading length than the Mercedes-Benz GLC: with seats fully folded down, the trunk of the Q7 is 11 in (16%) longer, and with the first row of seats upright, it is 10.2 in (28%) longer than the GLC. These two differences are the largest and most relevant for practical use.
What does this mean for usability?
The greater loading length of the Q7 makes it much better suited for transporting long items (e.g., furniture parts, long sports equipment, slats or boards).
Even in a seating configuration with the first row upright, the Q7 retains more usable loading length, allowing flexibility when transporting both people and longer cargo simultaneously.
The GLC, on the other hand, has small advantages for easy loading: the height of the trunk opening is 0.4 in greater and the narrowest width in the trunk is 0.8 in wider, which can slightly facilitate inserting very narrow, tall items.
The loading edge of the Q7 is 2.8 in higher, making lifting heavy loads somewhat more strenuous. Depth (loading edge to trunk floor) is the same in both models.
Practical Recommendation
If you frequently transport long or bulky items or value maximum loading length, the Audi Q7 is the better choice.
If you more often load and unload heavy cargo comfortably or need to push very tight, narrow items through the narrowest spot, the Mercedes GLC is somewhat more practical due to the lower loading edge and slightly greater narrow width.