I FOUND IT! THANK YOU ecount. Who'da thunk it woulda been under INFO??? It's a Setup option. Oh well - now it's working the way I want it to.

 

you're welcome. and you probably already figured this out but if you have it on audio screen, there are some actions that still return it to map like putting in reverse and having the backup camera come on. after that it's back to map. or taking a bluetooth call. hang up and it's back to map. you just need to punch up audio after you are done. i don't think there is any way to defeat that. but for normal use, it will stay on audio until you punch up something else.