There have been special sets sold only through the Porsche Museum Store. They are typically limited to 1000 sets and they sell out fast. As you might imagine a European model train club is populated by European car owners, Porsches included. Some of the club members have been at the Porsche Museum when these limited addition sets were available and made purchases.
Unfortunately, none of them come with track, contollers, or power supply. So if you don't already have that stuff, it is an additional purchase. The ETE Chapter that I belong to includes a special interest group that collectively owns a large modular layout that we set up in vaious museum venues and operate. We have just begun our annual 7 week Holiday Season run at the Blackhawk Automotive Museum in Danville, CA. Since this is an auto museum, it is common to see trains with an automotive theme running on the layout. I'll have a digital camera with me on the days that I am operating the layout. If any Porsche Trains make an appearance I'll photograph one for you.
My own Porsche Train is still being assembled. I bought a set of the 1/87 race cars that Porsche sells online and loaded them up on an empty auto carrier. A classy looking set up to say the least. At least one member has a 1/87 Porsche Dealership that has been placed on display at the Blackhawk Museum. BTW the Museum has some excellent Porsches on display.
You can see some pictures of the mmodular layout at the club website
www.ete.org