Trunk comparison: VW Polo vs VW Touran

Key Differences
The VW Touran offers a significantly larger cargo space with the seats folded down: +16.1 in (30%) more length than the Polo. Even with the first row of seats upright, the Touran is +13.8 in (53%) longer.
Conversely, the VW Polo has a significantly longer trunk with all seats upright: +12.6 in (94%) compared to the Touran. The trunk opening of the Touran is higher and wider: +6.7 in (25%) in height and +4.7 in (13%) in opening width.
The Polo has a more pronounced loading edge and partition height: the loading edge is +3.1 in (13%) higher above the road, and the depth from the loading edge to the trunk floor is +2.8 in (700%) greater in the Polo.
The narrowest width of the trunk differs only slightly (<10%, +1.2 in in favor of the Touran) and is therefore not critical.
What This Means for Usability
Transporting large/tall items: The Touran is advantageous when seats need to be folded down. More length with folded seats (+16.1 in), a higher opening (+6.7 in), and a wider opening (+4.7 in) make loading long, tall, or bulky items easier and make loading and unloading more comfortable.
Transport with full occupancy: When all seats are upright, the Polo is surprisingly more practical because it offers significantly more usable trunk length (+12.6 in). For trips with full seating and normal luggage, the Polo is often sufficient or even advantageous.
Loading ergonomics: The higher loading edge of the Polo (+3.1 in) and the greater depth between the loading edge and trunk floor (+2.8 in) mean more lifting effort and a larger gap when sliding in boxes or heavy items.
The Touran, with its lower loading edge, is more ergonomic here and facilitates handling heavy loads.
Brief conclusion: For maximum flexibility and comfortable loading with folded seats, the Touran is the better choice. For regular transport with full seating, the Polo offers a longer usable trunk. Ergonomically, the Touran has the advantage in everyday loading and unloading.