[svandamme]

production defect in oem wheels
it is possible

else : knock off wheels?
wouldn't be the first Porsche owner to buy a new Porsche put the oem wheels on the side the next day and slap knock off wheels on the car

metalurgy would be fairly obvious as to the break lines if it was OEM or knock off failure.


big rock or metal rod, caught inside the weel, very rare to get that , it would have had to be flying sideways under the car, weird but i supposed it is possible a front wheel throws something under and the rear wheel catches it?
unless there was a go pro under the car looking at the wheel, they would never know or find out if that was it


But most likely : very low profile tires, perhaps low pressure
pot hole or sharp and strong object
tire is impacted from below
not enough air space, suspension to stiff to react in time
wheel gets knocked from the inside and shard comes off.

Low profile tires are terrible choice for practical driving..They cannot aid the suspension, no tolerance for impacts and pot holes.