From a design standpoint the Viper still looks great and "original" after ten years. How many designs can hold up to ten years of production and still draw the looks a Viper does.... based on that, I say long term, the Gen I and Gen II cars will be classics.... Like I aspired to owning a Cobra when I was 20, todays 20 year olds seem to be aspiring to own Vipers.... a good sign.
This is going to sound a little silly, and may be considered a different topic. With the direction that many auto makers are heading (Hybrid power), I feel even stronger that our cars will for sure be classics.... boy I hope that the we can get gas for our Vipers though!
Honda is claiming they'll have a 50mpg, 400 HP Hybrid car out soon. This is going to be interesting... why?, because electric motors can deliver torque we only dream about right now. If fuel cells end up delivering the power for these motors, then we all better start praying that the fuel cells run on gas and not hydrogen or propane!
With that said, and if it occurs, big thumpin' V-10 monsters will be what people dream about when the cars they are driving are completely "silent". My dad just bought a Honda Insight, it is very "Eerie" when you pull up to a stop light, and it turns itself off (like a golf cart). The engine is so small you really do not even notice it is running.... when it is running. If all cars are like that in twenty years rest assured, Vipers will be collectible classics