This is the list of items I have and in order to make my car mount/dock.
HTC Mic from purchased from t-mobil 9.95
Bracketron from BestBuy 39.95
Bytech mini portable speaker from BestBuy 19.95 (optional)
Casset tape adapter 9.95
Mini USB Extension in order (optional)
3.5mm stereo speaker wire extension (Optional) Radio Shack 8.95
Htc mini usb headset adapter from amazon.com Ordered on in yet 5.95
Dual usb port car charger (optional) amazon.com 9.95
Currently it works great, noted I have a wire exposed hanging on my rear view mirror. The usb extension and 3.5mm speaker wire extension is to reroute the wires around the A pilar to go underneath the dash and back up to my mount.
I placed the htc mic in my sun visor and it's clear and legible using my cassette tape player as my audio output.
I got the speakers for my wife's van since I don't lile the fm transmitter especially when driving long distance. You have to keep on scanning different channels. FM modulators ore better, but too much work and may void warranty of vehicle if not installed properly .
I just keep my Bluetooth ear piece handy and and turn on the widget on if needed.
This is the HTC adapter you need. There are two mini usb out, one is for the HTC proprietor mic and headset adapter and the bottom is for the usb charger. The HTC mic adapter will not work by itself, you need to plug in a line out or headphones. It also have and optional 2.5 and 3.5mm jacks if you do not have the mic. In my understanding some of the older HTC phones does not have a 3.5mm jacks, that's why they cam up with this option.
With this device, you can charge your phone and have the speaker phone features.
I will update the images later when I have all the parts in.