Sorry, but you didn't!:) Alla Turca...(in turkish manner, as turkish things were supposed to be a bit in vougue at the time; see also the 'turkish' finale of violin concerto no 5 and the opera 'the abduction from the seraglio').
Sorry for ranting about. Anyway, I agree that it's probably not meant to be very fast, the tempo is indicated as "Allegretto" after all..
In english they call it 'Turkish March', which gives a good idea about tempo! A march is of course an accompaniment to marching soldiers, and is not meant as an exercise in speed.
I don't agree with what counterpoint says: "..Mozart notated the first and the fifth note of the beginning as gracenotes, that means, they have to be played very expressive!"
Rather, it was standard practice at the time to notate un-harmonious notes (i.e. not part of the chord) falling on strong beats, in the manner of grace notes. That is, it was purely an esthetic thing, the 'harmonically correct way' to notate, and had no expressive meaning.
The group of gracenote+8thnote+2x16thnotes is of course meant to be played as four 16th notes.