is it possible you were using the valet key?
and did it just cut off or did it act like it ran out of gas?
I also feel your pain on this....
I had a SSr brand new driving home from the dealership maybe 20 miles on the ODO and it just cuts off... left me on the side of the road and wouldn't start... i was pretty upset. Turned out that the detail people cleaned the engine compartment and got water into the air filter? or something and the sensors picked up water in the intake and shut it down.. maybe something similar