At the LA Auto Show this week, I spent time with a recent pre-release build of Android Auto using a Nexus 5 connected to a 2015 Hyundai Sonata. It's mostly the same as the version we were shown at Google I/O in June, apart from some minor refinements. For instance, the green, circular "a" logo that appears on the phone when it's jacked into the car now reads "Android Auto," and voice-based searches no longer cause a full-screen "listening" window to pop up — you just get a little pulsing "g" in the corner. The underlying concept, though, is unchanged: it's Material Design-infused Android for your dashboard, boiled down to the basics with copious use of speech output and voice recognition so that driver distraction is kept to a bare minimum. You're also locked out of using your actual phone when Android Auto is in use, another stab at limiting distraction by keeping eyes off screens and on the road.

Using Android Auto is a pretty great experience: it's simple, consistent, familiar (if you're an Android user, at least), and surprisingly responsive. Auto actually keeps up, unlike the tapping and waiting you do with many built-in navigation systems in modern cars. It seems to be only a hair laggier than using your phone directly, which is pretty impressive considering there's not a lot of processing going on in the car; all of the software and horsepower for Android Auto is piped over micro-USB from the phone itself. (The Google product manager demonstrating the system for me noted that the Nexus 5 he was using did get warm over time, but at least it's being kept charged.)

Spotify has an Android Auto app ready for launch.

In other words, Android Auto is coming along nicely, and it should be shipping in cars very soon. (Hyundai will only commit to saying that it'll happen at some point during the 2015 model year — but if you buy certain 2015 models right now, you'll be able to upgrade to CarPlay and Android Auto support once they're available.)

The problem is that the combined Apple-Google push into the dashboard exposes a patchwork of troubling fiefdoms inside the car's circuitboards. Different functions may or may not be controlled by Auto. For the ones that aren't, you must exit Auto and adapt to an entirely different user interface designed not by Google, but by Hyundai. Want to use Spotify? Android Auto has you covered; Spotify had early access to the SDK and already has an Auto app ready to go. But if you want FM radio, you inexplicably need to select "Return to Hyundai," drop out of Auto altogether, and select it inside Hyundai's far more primitive-looking UI. CarPlay, in many cases, will suffer from the same kinds of arbitrary divisions. There's no rhyme or reason to it apart from the hardware topography. Some functions are actuated by chips in your phone, some by chips in your car. That's an utterly meaningless distinction to the driver.

Hyundai's proprietary interface bears little resemblance to either CarPlay or Android Auto.

The most logical endgame is for automakers to publish CarPlay and Android Auto apps that support their vehicles' proprietary functions, so you're able to control everything from a single interface. The car's built-in proprietary system could still exist, serving only as a fallback if the driver doesn't have a smartphone connected. But there's really no sign that we're heading in that direction; none of the Google or Hyundai representatives I spoke with suggested that was a near-term option.

Instead, one of the better ideas might come from Volvo, which is using a big, portrait-oriented display to show its own interface alongside Android Auto (or CarPlay). Yes, you do still need to deal with two user interfaces, but at least you can see them at the same time.

It's ridiculous to expect car owners — most of whom are not dedicated technology enthusiasts — to use and understand two disparate user interfaces. It's also hard to imagine automakers fully relinquishing control of the user experience to either Apple or Google, but I predict that drivers will come to demand it: it only takes a few minutes of using Android Auto to understand that it has solved in-car navigation and entertainment in a way that car companies never have, and possibly never will on their own. Google currently shows 28 automotive partners on its Android Auto product site; Apple shows 29. One way or another, people will be exposed to these systems over the coming years. As that happens, frustrating, proprietary UIs will finally stop passing muster.

Basically, expect to really enjoy using Android Auto. And, at least for now, expect to be disappointed that you can't use it for everything.