[elav]

Read my recent post with the same issue. Based on my experience, I would start by reading the car and reporting back here any codes. OBD-II reader will only get you so far - so hopefully you have something that can read the Porsche specific codes such as a Durametric cable. If you don't have a reader, check the clutch pedal switch, fuses that I listed in my post, jumping the starter relay in the trunk, checking grounds, etc.