Add me to the list as someone who's suffering the same problem.
Mazda cx9 / iphone 8 / iOS 11.2 here. Worked once and now Disconnects and reconnects every 90 seconds or so when playing music ,Pandora, podcasts, etc . Interestingly enough I can make phone calls just fine thru the car Bluetooth link. Just not play audio
Phone pairs and works well with Jabra headphones. Seems to just be the car this problem exists with.
I've tried all the things others have.... Resetting network settings, re-pairing, etc. Seemed to me to maybe be the contact sych causing the issue so I tried disallowing contact sync when pairing but it didn't seem to matter
Hope the fix this soon very annoying used to work perfectly with my old iPhone 6s