BTW, just thought of something...it might be silly, but I would double-check and triple-check the placement of the motor one more time. I am sure you have already considered the probability of it being in reverse....who knows. I know when I'm stressed out it's easy to miss something.
After this though clb0099, I honestly don't think I would have any other ideas except to call it a day and be glad that you didn't get hurt or break something and bring the darn thing in to a qualified Porsche mechanic
Sorry, I wish I could have helped you out more.