Of course, being an obsessive Android tinkerer I couldn’t simply let things lie. So I downloaded the latest version of Google Car Home on my DROID X, then copied the APK file over to my SD card, and eventually to my computer. Then I copied the APK over to the MTP root folder of my Galaxy Nexus. You can see where this is going. When I tried to install the APK via the Root Explorer file manager, it popped out an error message. So as a last ditch attempt, I activated root permissions and copied the APK file straight into my /system/app folder. Eureka! The app showed up in my drawer immediately, and Google Car Home works just fine, as far as I can tell.
Here’s the Google Car Home APK if you want to skip the roundabout or don’t have a spare Android phone. Just copy it into your /system/app/ folder using a root file explorer. To use the easy method you need to be rooted, but those with stock Ice Cream Sandwich will have to use ADB to manually move the file from your computer into the correct folder. Here’s a guide if you’re new to ADB.
Disclaimer: this app, and the process for installing it, are offered on an as-is basis. Android Community is not responsible if you use it to play Angry Birds in the middle of the highway and end up with some angry people… or worse.