Continual problems with the brakes from new. Front and rear brakes always became stuck while parked during wet or cold weather - even if the car was only left for a couple of days.
Front brakes regularly found to be binding - the pads became stuck in the calipers causing the car to noticeably pull to one side when braking - very dangerous in emergency situations.
The handbrake was purely ornamental, with adjustment required every few thousand miles. I gave up getting it fixed in the end and just left it in gear!
Failed it's MOT each time - on brakes. MOT tester was always scathing about Fiat brakes.
Fuel tank sprang a leak - covered by a poorly publicised, almost secret recall.
At around 45k - it started to continually cut out at low revs (junctions and roundabouts). Eventually diagnosed as a faulty RPM sensor which was unavailable for months. This meant I couldn't drive it safely, so I had to use another car. Six months after it was replaced, the RPM sensor failed again - this time the car cut out while I was overtaking at 70mph. Only luck saved me from a very serious accident.
These problems were compounded by the poor dealer network which has questionable standards, yet sky-high prices.
Worst of all - when I complained about the faults my car had suffered (especially my near death experience!), Fiat UK weren't remotely bothered. Their appalling attitude means I would never touch a modern Fiat again.
The problems I experienced are such a shame, because the Seicento should be a brilliant car - it's got real character. The design is great, the execution isn't.
Great handling - leagues ahead of standard version (front anti-roll bar makes a huge difference).
Fairly good MPG - usually around 43mpg.
Probably one the fastest cars with a 1.1 engine - especially if revved quite hard. Very smooth engine (sounded good too, even with standard exhaust!) - easily capable of 100mph. Pulled better from 80-100 than it did from 50-70!
Even though it's supposed to be a town car - I always found it far better out of town, on a back road with lots of bends! The radiator is too small for town use - the cooling fan constantly went on and off in traffic.
Very good seats, albeit the driving position was slightly offset.
Interior lasted well - funky design with fantastic rev counter on top of dash.
Good sounding Sony CD player as standard.
A characterful, fun car, let down by dodgy build, poor dealers and couldn't-care-less importer. Quite tragic really.