For those of us living in Canada, you can use this from Canadian Tire
OEM Vehicle Specific Coolant, Volkswagon, Audi | Canadian Tire
I know that the Porsche/VW/Audi version is imported from Europe, but not sure who the specific manufacturer is. I haven't used this on my Boxster, but I used some of their other versions in other cars and all I can say is that they sure have some pretty colors