Our rear doors sounded like two gun shots every time they were opened or shut and the act of opening the doors is now totally transformed!
It appears the wear occurs in the bracket which bolts onto the body shell as it's mild steel. The pin and the arm are hardened steel.
The hole in the mild steel part is approx 8mm and the wear here makes the noise as the energy is stored up in the springs.
I purchased a 9mm drill - a 9.1mm would be best here though if you can get one. Re- drill the mild steel part.
Find an M8 bolt (I think) - these can be found holding the alternator on most fiats
. The 'shank' of the bolt should be 9mm exactly. Cut the threads off and drill a small hole - 2.5-3mm for a small split pin.The arm has a wierd slip ring in the hole which can be removed - making the hole just about 9mm - although it might need drilling a tiny bit.
If you have a 9mm drill you will need to carefully reduce the diameter of the new bolt-pins with course sand paper or a file - fit the bolt to a battery drill like a lathe and turn them down a fraction. (at your own risk of course
)Assemble with your new bolt-pin with some grease and you will have silky smooth door opening action!
I can get some photos if anyones interested.
I'm sure all the naughties fiats suffer from this problem.
Good luck!