Happy new year everyone - I'm back
On the 456 - stuff to look for:
1. Side window seals - a real issue on all cars, though partially remedied with the later M models. The door mechanisms are fiddly, over the years components fail - then tend not to be economically fixable (the new window workings are over $5K/side for replacement bits). Danny from the forum here is currently re-building my windows as we speak.
2. Front seats - have a pile of motors, wiring and other connections - which tend to fail from lack of use, or not work properly (seat should buzz forward when seat is tilted, and return to same position when seat straightened up). They all seem to break at some point. Bigger issue is when the mechanism to stop the seat sliding backward fails, and the seat then crushes the legs of your backseat (usually a kid or a stripper) passenger
3. Radiators - seem to blow up. Mine did. Replaced with an Aluminium jobbie from Qld
4. Front overhang means that any driver who is not careful can belt the nose on dips, bumps etc - radiator, oil cooler and aircon damage ensues.
5. Aircon controls - bubble, and electrics break. Condensors rust.
6. Pax Airbag cover - bubbles and sometimes shifts out of place, creating warning lights aplenty
7. Auto Trans - needs regular fluid changes - I think the scare about them breaking is overstated, but it one went, it'd presumably be expensive to fix if possible at all. Real torque tube drive has been an issue on some older cars.
8. Rear spoiler breaks. Constantly.
9. Cat converters die and cause engine warning lights, and ECU check lights
10. Front airbag lights seem to be disco random. Always exciting.
A 'well sorted' 456 is IMHO a lot of car for 80-100K. Any of the issues above cost buckets to fix - which is why you see these cars selling at 60K and up. I'd be wary of a cheapie unless you check all of above.