@Fabulist, you are correct. There is a "hand shake" between the car and Tesla when connecting to the Super Charger. Previously, the Model 60 (KW/hour) were marketed as a "local" vehicles and would not connect to the Super Charger network. Tesla also monitors each Super Charger for capacity, usage, and issues and updates that information to all vehicles "Trip Planner" navigation over the LTE connection.
Currently, there are no DC to DC high capacity vehicles that could connect to Tesla's Super Charger network. It may not be known to Fisker owners, but having both, I'm amazed at how fast Tesla can charger on the DC network. Bypassing the on-board converter, Teslas initially charge a 400VDC and over 200Amps. That is insane amount of energy. As the battery "fills" the amperage decreases, since it is more difficult to put current in the nearly full battery. The genius of the Super Charger philosophy is you don't need to fill the battery on the road -- just enough power to get to the next super charger. My typical charge on the road is about 30-45 mins to gain 150 to 200 miles of charge -- enough to reach the next Super Charger.
Tesla's position has been if someone makes a DC to DC capable of connecting to the Super Charger, Tesla will consider opening (I would assume for a fee). However, with the up-coming 300-400,000 Model 3's hitting the roads in the next 5 years, that position may change. In the US, Tesla is planning to open an additional 600 Super Charger locations (4-8 stalls each) in the US in the next two years, bring the total to nearly 1,000 locations or 5,000 stalls. All Tesla's come with a J1772, a 14-50 and 110 Vac adapter as well, and a number of hotels have Tesla 220VAC/80amp chargers for patrons. The Nissan Leaf adapter is available for purchase.
Before the Fisker owners jump on me, I still like my Karma and the Serial hybrid design. It is a viable alternative for some road trips.