The Fiat 500 is noisy in every form, though you can drown out the noise by choosing the Abarth version with its beefy exhaust note.
There's a fair amount of road noise, no matter what; and in the Abarth, lots of extra engine noise to go with it; the note is downright raspy, throaty and, when you're really on it, mean. In cruising it can be a bit more than you might like for conversation, but it's not loud enough to be annoying. And the bright side of it is that the cabin's so small, you're always very close to your passengers.
The best daily use for those back seats is as a parcel shelf, the seatbacks in their lowered position. If you absolutely must, however, the rear seats can, technically, hold two smallish humans. For a short time.
There's also no distorting that this is one of the smallest cars on the market; it's not nearly as spacious as a Ford Fiesta, for instance, and if you're of a typically American size, don't even think of trying to sit in the back seat.
Behind the rear seats, there's an equally small cargo space. The "500" figured hatch latch opens onto a space that's so compact--just 9.5 cubic feet--and oddly shaped that you're only really equipped for transporting scale models of pyramids and obelisks.
Fortunately, the front seats are significantly more spacious, though there are still compromises for the 500's sub-compact form factor. The seat position places the driver unnaturally high in the cabin, limiting headroom for taller drivers when the optional sunroof or glass roof is equipped. Shoulder, hip, and knee room are also more limited than you'd expect, or than you'd find in other small hatchbacks.
Once you're used to the 500's cramped cockpit, the colorful trim lightens the mood and the seats earn valuable feel-good points--although they're a bit too flat and stool-like for some tastes. And if you end up using the driver-side armrest from the passenger seat, you won't feel any more crowded than in the average coach-class 757, now, will you?