What year is your LS430? My 2004 LS430 UL Nav has voice turn-by-turn and is quite acceptable to me. Suggest you read your Nav System Manual (if you don't have one, then sign in, register, and order one from mylexus.com.

 

If you get a BT45 (or similar), ANY audio your phone outputs will be output through the vehicle's speakers. So yep you will hear your phones navigation voice through your car speakers.

 

Jayclapp I was going with the assumption I had no turn-by-turn as Daspyda said he didn't. I haven't used my navigation yet so I will see when I use it. I have a 2005.

 

Thanks, Mobius1 this will be my first mod!

 

Yes, if you are listening to music, the app will reduce music volume momentarily while it tells you what to do.

I used to look at the map in addition to listening for the prompts. Several months ago, I weaned myself off that by paying more attention to the road and listening more intently. This makes more aware of traffic, particularly when approaching an intersection for a turn.