I have to politely agree with the others here (well, except "gonefishn1" which I can only hope and assume was sarcasm) on the advice. I've seen many reports in forums and groups where people had things mounted like this (or to the windshield) and in a relatively minor accident (bad enough the airbags go off but not so bad that they would have been injured) they sustain bad injuries because when the airbags explode (because that's basically how they go off) the object flew at their face or arms at breakneck speed. Sorry, but that's just the facts and the others who have warned about it are right. Alas, it's your setup and your body/life to risk...unless you carry passengers, then it's negligence..
The remote session via your stereo's head is really cool, though!