Hello,
I would not get a Lexus one. I have an 07 ES350 with the nav, I can not talk to the system because it thinks I am speaking Greek, and the Nav portion works great if you are stopped when you want to make any changes. I bought mine from out of state, and the local dealer is not very good, when you read in between the lines their sales people say: If you had bought it here... BUT...
I have a portable Garmin works great even in bluetooth and I can drive and change destinations or have the passenger do it. Using the Lexus system we have to STOP. Wish I knew how to change that.
Get a portable, I can put my Garmin in the ashtray and not even look at it, the voice commands will tell you when to sneaze.
Best of luck.
The above are just my opinion. and I was so hard headed to only get one that had the Nav system. Wont do that again.