I have a rust-free 23-yr-old 164.
they seem to survive quite well in England too?
Interesting to learn about Arese, thanks Symon, I think the 164 was built there too.
I've always thought the 156 was made quite differently to the similar-aged GTV, like it had a different production-engineering team. Seems to be more parts-sharing between 164 and GTV - electrics, trim design/materials, even nuts and bolts. The 156 has a more modern selection of parts, like there are different suppliers and subcontractors (same bolts as FIATs, for example).
So - seems on balance we can summarise:
- 164 (1988-1996ish) and GTV (1996ish-2005), only localised rust, many galvanised panels
- 155 and 145/146 made between above dates (somewhere else?) - good?
- 156 and 147 1998-2005, disappointing for age, sometimes widespread rust in floors and roofs (I've seen the latter) but doors and other cosmetics OK.
- Anything else from the 80s or 70s - rust anywhere... Take my Uno for example. Same age as my 164 and lives in the same or better conditions but has had many rust problems over the last ten years. Actually Unos were often rusty in wet-and-mild NZ at about ten years of age (sunroof, door bottoms) but I have yet to see a rusty 156 in NZ, so I think even the 'worst' of the bunch is still better than the 80s average.