My guess is that current cars, although efficient, don't engender the same 'connection, as did cars of the past ......maybe their very unreliability, and the engagement and achievement needed to run them were actually part of that bond (an old A35 or Anglia being coaxed and prodded round a tour of the Highlands returned a heroic pal .... if a modern appliance didn't do it faultlessly it would be a miserable failure) ..... I think there will be considerably fewer drivers with the inclination to preserve.
Added to this is the proliferation of models and continuous change within models that will make the job of the future small company 'aftermarket support' a real struggle ... we mock the storeman behind the counter when they ask for the reg or vin-numbers as a first word, but such is the mass of ongoing parts changes that a month either way and the bits won't fit ... not like britparts selling swivel joints for Landies that fit everything in the last 50 years.
I reckon that, aside from the odd example nursed along by a masochistic obsessive, a Classic Car Show in a field in 50 years will look remarkably similar to one next weekend when it comes to the cars.
K