I would have no trouble sleeping at night using G40 in any Porsche made since 1996.
In 1996 Porsche just ike VW released G12 which was a full OAT coolant, from then on they ( VW and Porsche ) have used the same coolants.
G40 would be = VW G12++ or G13, SAME INHIBITORS
Since 1996 the VAG group has had towns of different coolant that are really much the same .
G11 = IAT
G12 = OAT
G12+ = OAT ( Only reason it was released is that it could be miscible with G11 and G12 was not )
G12++ = HOAT, the same astuff as G12+, but with Silicates
G13 = HOAT, the same as G12++ but with 20% Glycerin.
And the newest, G12 Neo = Same as G13 but with Phosphates.
Since the beginning of time until 1996 = IAT
1996 - 2012 = OAT
2012 - Current = HOAT
Bottom line, you can use G40 no problem whatsoever.