"If I were you, I'd also insure that you discover how many stage 1 and 2 redlines the engine has endured just for your own knowledge as a baseline... and to see how the last owner(s) treated the car. If it's been stage 2 redlined a lot or recently, you can walk away. You find this out by having it hooked up to a OBD reader from Porsche."
I have been having fun with my Durametric software/OBD reader, I checked with them and it looks like it will sorta tell you how much the engine has been in at and beyond the rev limiter. The software gives you the number of ignitions the engine has been at the rev limiter (Range 1) and beyond the rev limiter (Range 2). I am not sure how this information on number of ignitions as a measure of time at redline differs from the information from a Porsche OBD reader.
Ed