Trunk comparison: Seat Tarraco vs VW Polo

Main Differences
The SEAT Tarraco offers significantly more cargo space in length and opening: with the seats folded down, the Tarraco's trunk is 19.3 in (36%) longer than the VW Polo's, and with the first row of seats upright, it is even 18.1 in (70%) longer.
The trunk opening of the Tarraco is also 5.5 in (20%) higher and the width of the opening is 9.1 in (25%) larger than the Polo's.
In contrast, the interior cargo dimension from the loading edge to the trunk floor is 0.8 in (33%) larger in the Polo than in the Tarraco.
Smaller differences: the Tarraco's loading edge is 2 in (7%) higher above the ground, and the narrowest trunk width is only 0.4 in (1%) larger in the Polo — both negligible in everyday use.
Impact on Usability
For long or bulky items (e.g., slats, furniture parts, skis), the Tarraco is clearly more suitable: the significantly greater interior length with folded seats as well as the wider and higher opening make loading and storing long and tall cargo easier.
The wider opening reduces angle and space issues when sliding in bulky parts.
The deeper cargo space in the Polo (greater depth from loading edge to floor) offers the advantage that loaded items can lie deeper and thus be less visible or better secured — practical for groceries or suitcases that should be "recessed" into the floor.
At the same time, a deeper loading surface can slightly complicate lifting/placing heavy items, especially when the vehicle's loading edge is higher.
Conclusion: Those who regularly transport long, tall, or wide cargo will find the SEAT Tarraco to be the clearly more practical solution.
Those who mainly carry smaller luggage or prefer a deeper, somewhat more protected loading area will find the VW Polo to be a more compact, but less flexible option in terms of volume and opening.