Looks like a neat setup.

 

Functionally:
You say you don't need to touch it while driving, but what about zoom in/out, display POIs, or finger scrolling the map to see another part? Those are the kind of things all OEM navs expect someone to do.

Cosmetically:
It's no secret I don't like the interior of the Yaris (sorry), and the small Garmin against the sea of grey plastic behind look kinda odd to say the least, but that's subjective. I think it would be better up higher, maybe still on the dash, but you can see it above the steering wheel and can control it if needed, but maybe the Yaris interior doesn't really permit that or it would be too far away from you, I don't know.

I think you're making the case as to why center guages are a bad idea. The speedo is more important than the nav.

Edited for truth.

 

Possible Theft magnet? Is this unit removable or fixed?

 

Every OEM nav starts up with a warning screen saying to never operate while operating a moving vehicle. Do people still do it? Of course, just like they eat, put on makeup, and talk on cell phones while driving. And yes, I can and do operate simple functions while in straight ahead motion (and my eyes are closer to the road than most OEM units).

I'm aware of the negativity to the Yaris interior by some. It's understandible from Lexus owners. I personally love the interior (and I live in dozens of different cars all day long at a dealer). There's just something I love about it's simplicity, durability, and functionality. And I like modern economy cars.

I did play around with other placements and it just looks flimsy and out of place attatched on the window or dash where it obstructs view. I purposly didn't want it up high above the wheel. It just looks ridiculous that way.

The Nav has a speedo. And btw, the nav is more important than the speedometer.

 

It's easily removed when I'm not driving. It's clipped to the cradle on a ball jointed arm with suction cup that came with the unit. It's attached the same way as you attach the suction cup to the windshield.