Re: Here is the golden question.
In my view, most cars which become true classics do so because of the looks and not the engine since the development in engines will render old engines obsolete technically. If you take an old Ferrari (25 years +) most will today be outperformed by a nimble GTI but it is still a Ferrari and that name is magical in it´s own right. Same goes for older Maseratis etc. And really, how many sports saloons have made it to the hall of fame?
The 166 is a great car and I deeply love mine, but a classic? I seriously doubt it. Especially since the front lights etc. are not "universally" beautiful. As for spare parts, that shouldn´t be a problem in the foreseable future since they are still manufactured and will be for some time. The 166 is still used as a patrol car by f.ex. the police in Rome.