Hey anyone know if its possible to improve the bluetooth sound on the f series of avics? Like adding a better mic or something, ideas would be appreciated

Have you been reading man? Right now there is no definitive way to improve BT quality, here's a few things to try:

Update phone

Pair phone with volume down

Turn off echo cancel

Throw unit out the window of moving car

I have a Z2 and it was notorious for mic problems. A few things that helped up in the Z-series forums were:

1) when pairing the phone, make sure the volume is turned less than 1/2 way on the phone

2) set your output to come from the left side only

3) dont turn the output for the voice very high, it can ricochet off the other door and into the mic, causing an echo for the caller on the other end.

Try these things and if they dont work, dig around the Z-series forums. Alot of things were tried and there's plenty of info there.