I have a 2017 300C and the sound quality is horrible during phone calls. On my end, I hear static but the person on the other end hears a loud echo. It's so annoying that we have to end the conversation because I can't hear through the static and they can't hear through the echo. I know it's not the phone because I have paired two other phones and the issue still exists. Is this a known issue? Also, when I transfer the call from the Bluetooth to the handset, the media/radio no longer plays.

I had a 2016 300 and didn't have any of these issues! In this case, newer isn't better. I would expect improved and not decreased quality from one year to the next.