I had cracks in two ignition coils. Porsche part# is 98060290403. They run about $150-$160 each x10.
However, Beru makes them. If you research this company, they have outstanding reviews.
Next Day Auto sells them at about $360 for all ten shipped next day air.
800 miles later, no issues.
Decided to change all plugs. Tip: High Octane race gas does not have the needed cleaning additives found in good pump gas such as Chevron with Techron. I recommend a bottle of Techron (18 oz) added with a half tank.
After changing the plugs, the rough idle at start up is gone... like new again.