Two problems related to coolant leaking have been reported for the 2005 Porsche 911 Gt3. The most recently reported issues are listed below.
Engine coolant leak led to complete upgrade of all engine coolant fittings due to widely known problem with catastrophic engine coolant loss from sudden dislodgment of coolant fittings from engine. I have seen no fewer than three other identical models suffer such coolant loss while at speed. My repairs were done to prevent a potentially dangerous and/or costly incident from this design flaw.
Paid out of pocket for preventative coolant fitting welding. The epoxy on oem coolant fittings is known to fail, potentially leaking coolant on to the rear tires or road surface behind the vehicle without warning, creating a potentially deadly scenario.