I actually call it...911 Turbo.
My (now) 4-year old son called the 911 Turbo "EL TURBO" a year or so ago because he couldn't say Neunelf in German.
Since that time, my daugther, my son and sometimes me too, call the 911 Turbo "El Turbo". It is a funny name for such a car but it actually is pretty accurate, don't ask me why.