Are there sounds in Mozart that you actively dislike?
Today we already found a few in an Allegro spiritoso - remember that means "with wit." For the student it was a whole measure trill accompanied by a highly dissonant Alberti bass. For me it is a single unaccompanied quarter note: I simply don't believe in such sounds and wish they would evaporate.
As usual these turned out to be critical to the drama of the piece. He sometimes makes his point by being deliberately ugly. It's not too strong a word.