The short version:
1993 NSX acquired as fourth owner 2 1/2 years ago with 70K miles. Car now has 160K miles. Driven daily, tracked occasionally. Never had a serious issue, only one or two minor and common NSX gremlins (replaced a window regulator and last week BrianK repaired my CCU whose leaky caps were causing the display to flicker.)
The original clutch lasted 130,000 miles. Replaced it with an OEM clutch and also replaced clutch master and slave cylinders. Timing belt/water pump service was done at 80,000 miles in Feb of 2004. I'll need a new belt in about 6 months or so. I wonder if that will be some kind of record.
Preventative maintenance:
Coolant changed every six months (thats about every 20K miles)
Oil and filter are changed once a month. OEM filter and Amsoil ATM 10W-30. Also using Auto-Rx with every oil change.
Tranny fluid changed every six months. 2 parts GM Synchromesh Friction Modified and 1 part regular GM Synchromesh.
I only use Chevron or Shell gasolines. (The only
Top Tier brands sold in my area.)
Redline SI-1 Complete Fuel System Cleaner is used about once a month.
Interior regularly treated with Lexol products. Exterior is washed fairly regularly as it gets dirty fast with whatever car wash is on sale. (Soap is soap) And waxed every 3 months with whatever synthetic wax I have lying around at the time. I don't care what your mommy told you, Carnauba is evil, overhyped, often overpriced and the last thing you want on a modern clearcoat finished automobile. For in between washings I use Pro Honda Spray Cleaner & Polish.
That's about it. Just change fluids regularly, maintain the interior and exterior finishes and follow recommended service intervals and an NSX will probably outlive its owner.