Was there a court case? When did Porsche challenge the state franchise laws?
As I recall, they wanted to set up regional service centers and possibly regional inventory banks. Many Dealers were not in favor.
It took a second set of search terms to cough this up:
"Porsche dealers reacted with hostility and a flurry of lawsuits when Porsche A.G., the West German maker of expensive sports cars, announced plans last month to abolish its franchise dealer system in the United States. Porsche, at the time, said consumers were dissatisfied with existing dealers. The company also said it wanted to prevent price gouging on popular models by dealers and to set repair standards. The company was planning to cut in half the commission it pays on each sale and to establish its own sales agents and company-owned sales and service centers. It did not publicly estimate what savings, if any, would result. "
http://www.nytimes.com/1984/03/14/business/the-porsche-franchise-fight.html