Top Gear did a segment a few years back on Italian cars and explain that after the war Italy had very little iron stocks so most of the cars were made from recycled bridges and steel which was cr&p metal full of impurities. Sheet metal would start to eat itself before your eyes. Had a funny skit were May bought a second had Fiat and parked it outside his flat only to find a pile of rust the next morning. I had a nice Fiat 124 Sport in the 80's. Great car but found some bodgey rust repairs. A previous owner used shade cloth the support the bog in some areas. It had rust holes on top of the guards. Some before and after shots before a flicked it.