if you leave it on audio, it will start on audio, but every other screen will revert back to MAPS on start by default. You can't get it to default to EV trip info by default for example. Many of us find a good compromise in using the picture beside picture function (PsideP) which speeds access to the trip info etc. To get PsideP:
when viewing true MAP screen touch the "Compass" icon on the right....
select the PsideP and touch SET...
then once selected the TAB ( bottom left ) will allow you to select which data set to display...eg EV trip etc
hope that helps
HJB