Apple is very aware of this issue, and has been since September. Wish I'd researched the threads before buying the iPhone 11 Pro. Static in my car while on Bluetooth, and Siri cannot be heard through the car speakers unless it is for Directions via Maps. Visited the Apple Store 6 times, they replaced the handset 2 times, and then told me not to come back!!! Told me to speak with AppleCare via the 800 number.
In the past 7 days, I've spoken with AppleCare 4 times, recorded and sent logs twice. Each time, I've been told to sit tight and let the developers look into this problem Apple pretends not to know about. Each tech tells me they will call me back within 24-48 hours, and they never have.
Today, I asked for a new handset and to reset the warranty clock to zero bc my new phone does not function as marketed. One tech said, "ok" but let's wait for the technicians to reply first. Subsequent techs told me they will no longer replace the handset, and that I must sit and wait for an update from Apple. Frustrating!
Not holding my breath on a fix from Apple anytime soon. Online searches show this problem popping up in online forums right after the iPhone 11 launch. BTW, have a friend with an iPhone 11 (not Pro like) and his acts the same way with our BMW 3 Series and our Honda Odyssey, two pretty ubiquitous vehicles.
Poor execution, customer service and customer service messaging (just wait for us, tick-tock runs the warranty clock)...am about to put the 11 Pro back in a drawer and use my iPhone X. May even just take the loss and dump the 11 Pro on Ebay out of frustration. Nice camera and better battery, but total fail at its primary functions of vehicle phone and text platform.