Trunk comparison: Fiat Panda vs Hyundai IONIQ

Key Differences
The Hyundai IONIQ offers significantly more cargo length: when all seats are folded down, the trunk of the IONIQ is 20.5 in (≈47%) longer, and with the first row of seats upright, 14.6 in (≈69%) longer than the Fiat Panda.
The Fiat Panda, on the other hand, has more favorable vertical dimensions and loading conditions: the height of the trunk opening is 8.7 in (≈33%) larger on the Panda and the depth from the loading edge to the trunk floor is 2.4 in (≈50%) greater than on the IONIQ.
Other differences are minor (loading edge height of the IONIQ +2 in / 7%, narrowest width +0.4 in / 1%, opening width +2.4 in / 6%) and thus insignificant in practice.
Impact on Usability
Because the IONIQ offers a significantly longer cargo area, it is better suited for long items (e.g., furniture boards, skis, long boxes) and generally for users who frequently need larger cargo volumes. Folded seats provide a noticeable increase in usable length in the IONIQ.
The Panda scores in practical loading: the higher trunk opening and greater depth mean more vertical space and easier loading of tall or bulky items (boxes, suitcases, taller cargo).
Additionally, the loading edge is lower on the Panda (IONIQ +2 in), which makes lifting heavy loads easier — this can be more important in everyday use than pure length.
Width differences are minimal and have little impact on usability.
In summary: For maximum cargo area and long items, the IONIQ; for easier, more ergonomic loading of tall or heavy items, the Panda.