I was discussing the TM3 with someone who is interested in buying one. He asked me about an "avoid highways" mode - as he often likes to take back roads instead of Interstates. I was pretty sure one just clicked a menu option. But the Tesla nav only supports "Avoid Ferries" and "Avoid Tolls". So egg on my face... Is there a decent way around this short of running a parallel nav app in ones cell phone or other device? Maybe running something on the built-in web browser?