So, I recently bought a Japan-imported Honda Fit, and it came with a Japanese Gathers VXM-175 VFEi head unit. 

It has a button to switch to CarPlay in the audio source menu, but it is always greyed out, no matter what I try.

I've tried changing the settings from iPod to Carplay, connecting to bluetooth, disconnecting from bluetooth, plenty of different lightning cables, went into the "dealership settings" and tried re-enabling carplay, even changed the region on my phone to japan, still nothing. the carplay button just does not become clickable no matter what i try

Anyone got any experience with this sort of stuff? Just enabling carplay would save me the $600 ish it'll cost me to change the head unit entirely