We don't mean to scare you, but at the same time, if we don't stress the importance of what that flashing means, people will go and drive their cars anyways until they start hearing bad noises that mean big $$$$$.
You may have some correct suspicions about why the car seems to be running roughly, but that rough running may be causing enough shifting/vibration that the car is telling you "hey, got a potentially big issue, get this figured out before you go any farther, ok?" when it flashes at you.
Since it seems to be only happening at startup I figure the car seems to be settling down and the situation bringing about the flashing is going away after a time. But the problem is that over the long term whatever is causing the flashing could be taking its toll on the engine or other components, so do get it looked at. Better safe than sorry...we all know these engines and many of their components aren't cheap, no sense in possibly costing yourself more money down the road by ignoring it.
If you can purchase a code reader and diagnose it yourself (does not require starting the car, so it's safe), you'll save yourself some money and give the mechanics a good head start by saying "I have this code, this code, and that code. I looked them up for Porsches and they mean this, this, and that." This also prevents them from trying to trick you and claim that there are problems where there are indeed none. You can also tell
us what these codes are so that people on the forum can advise you on where to start looking for problems. We're here to help (not just scare
), so use us.