I actually love this device so much. For years I have been annoyed with my current car setup and looked for a cheap way to use blue tooth (as it is not worth paying for a brand new system for my old car), plus it was always annoying having to plug my audio jack every time I was hopping in and out of my car (especially during errands/shopping trips etc).
If you have a USB plug in your car, or use the cigarette lighter (socket) it will automatically turn on and be ready to use.
NOTE: when setting up blue tooth to your phone or device - the instructions said a specific name for the Bluetooth device, but turned out to be a completely different name!
So be aware of what available devices already show up on your phone/etc before powering up the USB blue tooth device if you are in an apartment block etc.