In short, if you're like me used a Nexus 4 with the original Google Car, the device is not to be used: 80% of the trials (ie placing the phone on the charger) acknowledged with a red flashing fast and the N4 is not loaded.
I have numerous trials carried out and sometimes it works quite well (ie 3-4 attempts succession function and you think you did the trick out), then it is no longer 15 times in a row, a "move" has brought nothing in my experiments, only a total removal, wait 5 seconds and re-hang up has sometimes led to success ... but wait only sometimes.
Total unnerved I have now given up, I can see no pattern / position or no approach speed / angle at which it works satisfactorily and above all reproducible.
For me it is really the idea that you simply plan puts the phone and it will be loaded. If you have to try it first for 1 minute, I might as well tuck the cable, keep my nerve and I am yet to faster.
The results of my tests without Bumper were slightly more successful, that is for me, however, of secondary importance, because I want to use the Bumper.
Conclusion: I'll send it back and wait for the release of Google Wireless Charger.
