There are actually more than one grommet for these. The grommets at front fender and engine compartment are shaped differently than the ones in the center rocker supports.
The end ones are proprietary to Porsche, they have a angled component and shoulder.
Center ones are more typical circular grommets.
If originality isn't important you could just buy bulk from Mc Master. I have some Genuine used originals if you are interested.
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