I know, it may be too late for, but have a look at this vid - maybe it will help you to defeat this navigation system's behavior:
I guess this doesnt work for all the nav system??
How about the Pirelli Scorpion Verde or the Nitto? The Kumho KL21 H are on sale for $127 each if going on value. I think a sporty tire will be better for the RX since the suspension is very comfortable. I also see some Nokian Z SUV tires for $109 each. Looked pretty nice and the brand is good.