2016 Edge

My wife and I have identical phones, we both use Tracfone. It suits our needs very well, I paired my phone and so far everything works well, all my contacts downloaded and my phone is recognized when I get in my vehicle. My question is if I pair my wife's phone and download her contacts [many are the same with a few different ones] I would imagine when she drives it would pick up her phone, what happens when we are both in the vehicle with our different paired phones turned on ? Do they both work and send and receive calls ? what would happen [just curious] if we both got a call at the same time? I looked in the Sync manual to no avail. Thanks for any advice.