In browsing some pictures today I noticed both hex head and allen head for the M8x20 bolts that hold the trombone oil cooler in place in the front fender.
Likewise for the screws that hold the oil line clamps in the front fender. Seen both types of heads in photos.

What's correct? Porsche just says "Pan head screw" in the parts manual for the trombone, but they do say hex head for the M6 bolts for those rubber/steel clamps in the fender.

Ravi