What are peoples' opinion on preventative maintenance?

[jmatta]

Changing oil at 12,000 mile intervals is over twice as long as any of the knowledgeable folks on this board would recommend.

I find all of this very interesting since I plan maintenance every spring and fall on my '02 S. My car now shows just about 17k miles, but I'm already thinking what could be replaced due to age, not wear. I've also updated the car with the LN products that I could easily install and am highly considering the IMS update, though my clutch is just fine. My friend is a wizz mechanic (Porsche owner) and this is something he may attempt to do to my car in our free time. His 996 had RMS issues, but that was replaced with a 997 CS...all his other P-Cars are air-cooled.