I purchased the kit when I bought the car a couple weeks ago (17 Mirage SE) and I got the kit to the house today.
On the top page of the installation instruction sheets says in all caps:
IF THIS IS BEING INSTALLED IN A MIRAGE WITH DISPLAY AUDIO WITH SMARTPHONE LINK RADIO HEADUNIT THEN A REFLASH OF AMPLIFIER MUST BE PERFORMED. FAILING TO PERFORM THE REFLASH CAN RESULT IN ISSUES WITH THE SOUND QUALITY THAT COMES FROM THE FACTORY SPEAKERS.
If anyone has installed this on their '17 (SE or GT) can you comment on sound quality or if it is a real necessity to have the amp reflashed? I know I'm probably going to have to head back to the dealership if the sound is really awful but if anyone has some insight that would be awesome.