Today, I was going to write a review of the HTC A100 with the HTC One.

In summary, it doesn’t work. The end.

Ironically the A100 does work fine with other brands eg Nokia Lumia 620. So as a workaround I used a Samsung HS300 Bluetooth and plugged a 3.5mm to male 3.5mm cable from the headphone jack into the car aux jack. That worked just fine.