Soundbot offers its Soundbot Bluetooth Car Adapter, model no. SB360, for $13.99 with free shipping. (KickBOT via Amazon charges about the same for Prime members.) That's $26 off list and the lowest total price we could find. It features on-board dedicated call, previous, and next buttons, 10-watt dual port 2.1A cigarette lighter power adapter with two USB charging ports, built-in mic, and 3.5mm AUX cable.