Hi
@laurajb The only time in 2 years that I've been on a call when I get into my car, the call remained within my mobile until I started the car and the audio unit had initialised, at which point a message appeared on the screen to transfer the call to the car bluetooth and I had to accept/acknowledge the transfer.
You have to ask yourself how often the scenario you painted is likely to happen? I know both your cars should behave consistently so I understand your query.
Then when I press on my mobile & the audio output to switch to i30
Presumably your audio unit starts up with your car and isn't turned off by default?
If you & other half both have iPhones (at the same Ios version?) it suggests the difference is in the headunits. You could always ask your dealer, seeing how new your cars are