On to the value in 10-15 years [or about 2030].
Agreeing that last year had record prices, and if you were going to sell that would have been the time,
I think the Gen 1 NSX will drift around the prices out there now, plateau, drop -- but then continue to climb.
Here's why:
In 10-15 years, a "no bells", gas powered, stick shift, rear wheel drive car will be a complete rarity. There are hardly any now.
Add in an aluminum body, the history, rate of cars crashed, reliability, relatively low production numbers, a sense of a
"throw back" to an earlier era [something like the resurgence 60's muscle cars] and you have a limited commodity.
Keeping up on scheduled maintenance will be key. I don't think it will have to be bone stock, but matching numbers, stock engine and original paint will get the best return.
And I'm biased, of course.