I have a 1999 996.This is my third Porsche, previous 1989 Carrera, and a 2001 Boxster.
The Porsche Excellence Buyers guide $14.95, and you do not have to subscribe to the mag, goes covers each year and any possible mechanical issues that may arise, with any particular year and model.
Also Pelican's advise on what to look for when buying a Porsche. I found the best way to have a great piece of mind is to get as positive look at the car as possible.
I paid three hours worth of labor to a Porsche mechanic (code reader in hand) and took him with me to evaluate the car. As many will tell you a couple hundred dollars can save you thousands.
