Yes and no to the original question.
Some Mk2s will become a classic but they'll be top end 16v, G60 and Rallye.
Mk1 Campaigns have already sealed their future, as have Clippers and Mk1 Cabs. Cabs always have a future in classic cars.
Modified cars won't a future though. They are a labour of love, and when they lose that loving owner they'll rot just as quick as any other car. The reasons they will lose that owner is because people grow older, get more responsibilities, get kids etc. So the pride and joy in the garage will eventually give way to a more practical car.
The trouble with the Mk2 Golf at the moment is that there are simply too many around. We need another 500,000 to be scrapped before they acheive any sort of classic status.
Performance is a non issue. Rarity will be the issue. If performance was important no-one would resotre VW Camper vans.
Tin