[Android Q&A, Help & Troubleshooting] kevinaj:
I made the same mistake of purchasing one. I have been unsuccessful in trying to root it. Z4 will just freeze the device requiring a power cycle. I attempted to connect via USB but did not have any luck using this method either. The problem is that the radio runs both USB ports in Host mode. This keeps it from showing up as a device when you connect it to a computer. I have tried both the front and rear ports with Windows and Linux.

I did manage to get the Android Market app installed. It took a good bit of work and involved copying the Google apps including first boot to an SDcard and sideloading them. The first boot app did break my home button, it currently does nothing and I can't figure out how to re associate it with the launcher.

Once I was able to connect my Google account, I was able to sideload the market apk. Of course, this required working wifi. The dumb device is configured for wifi using a wpa_supplicant file which specifies that 802.1x authentication is required. Seeing as I'm not using this on my wifi, I needed an app called wifi fixer to override this setting. I also needed to setup an unsecured wireless network because I couldn't get wifi-fixer to connect to a wep or wpa network. Once connected, the wireless was very spotty but worked long enough for what I needed.

After all this was completed, I was able to download an offline navigation app, copilot live, that would allow me to use the device as a nav while I wasn't sitting in the driveway connected to the wifi. I did try connecting to my rooted DroidX with CM7 using wifi tether but could not get the radio to complete the connection.

As shassouneh pointed out, it boots into FM Radio every time its powered on. This allows it to start playing music quickly, but is very annoying. I typically stream music from my phone over bluetooth which requires the volume to be much louder than when listening to the FM Radio. When you start the vehicle, the volume is remembered and will be deafening. The FM radio application is very buggy and it will take several attempts to save your radio presets with an acceptable name. It tries to use the digitally broadcast station information as the preset name, but often it just returns garbage. After trying some twenty times, I was able to get most of my presets to read the frequency and the FCC station name. (ex. 93.1 WPOC).

The touch screen is very disappointing. It's a low-quality restive type which requires that you touch below the point you're aiming for. This makes getting to buttons at the very bottom of the screen a challenge. I tried calibrating the screen, but was sent into and endless loop of touching the cross-hairs...

The "Phone" app has all the bluetooth configuration including pairing, contacts, music, etc. it is very rudimentary. The radio frequently fails to connect to my phone on its own and needs to be forced to connect. Sometimes the play button will start the phone playing music and other times it won't. I haven't found a rhyme or reason for it yet. It doesn't support AVRCP and as such you get three buttons when streaming music over bluetooth: Previous, Play/Pause, and Next. There's no indication of which song is playing nor is there any way to browse the music on the phone from the radio.

Overall, the device is absolutely terrible. Perhaps if I could root it, I could fix a number of its annoying characteristics and it wouldn't be so bad. I was most disappointed by the poor wifi and the FM radio at boot. There is such potential here to make an awesome device... Do not waste your money on this piece of garbage no matter how tempting it may be.