Will the trunk of a Fiat Panda hold four carry-on suitcases 22x14x9? Can't seem to find specs and car rentals sites are not accurate.
No. Three will be tight, maybe not even.
If you put the seat backs down, maybe. Are people going to be in the car at the same time?
The Panda is a tiny car. I would guess that you might get one case of that size plus a couple of carryon totes in that trunk. When my son and I went to Ireland, we had an Opel with a similarly sized trunk. We had to carry one of our 22" cases on the backseat because we just couldn't get both to fit in. We could have put our carryons in the trunk as well but we needed them throughout the day, so we ended up with most of our luggage in the backseat.
We get 2 roll-a boards and 2 back packs I the rear storage area and that leaves a little room for souvieners.
I didn't want to take a chance on the Fiat Panda so rented a Ford Focus. Better to be safe than sorry for three weeks. Thanks for your responses.
Please get a car big enough for your needs. Please don't put suitcases loose on the back seat. In an accident or sudden stop they act just like un strapped in people and can fly forward like missles and seriously hurt or kill people in the front seats.