What did I do now?

[thstone]

I'd flush it well and start over with Porsche (or Prestone) but I wouldn't mix them. The last thing you want is to have a coolent incompatibility and overheat the engine. Not saying that is what will happen, but its definitely not worth the risk.

[clickman]

I'm not saying what you put in is incompatible, but as a previous poster mentioned, incompatibility could lead to gelling, and you do not want to have the cost of having to remove gelled coolant from throughout your system. Not to mention the possible engine damage from overheating...