Why cost solutions in the dealership actually 10-100 times?

Have always read that it was BT audio worse than over cable. So either I have been what is wrong or I have misunderstood something. Unpack products connect and pair with mobile phone lasted 2 minutes and already ran the Audiobook with a deafening volume over the boxes. The AUX input was set at the level of the jack of the iPhone.
The volume is adjustable on the way home spot, before use (see instructions).
The telephone quality is sufficient. My installation is not the best ones, but I usually do not telephone, so I did not choose the installation afterwards. When testing my arm was basically always in the way.
For those who just annoy bright lamps in view of the driver like me, with this device, I find the light tolerable. (Did it anyway installed so that my hand at the wheel of this obscured)