ATC LLC via Amazon offers the Lumsing Bluetooth 4.0 In-Car FM Transmitter with Charger, model no. 4018913, for $23.99. Coupon code "B7O6P9SZ" cuts that to $17.99. Plus, Prime members bag free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs an extra $6.03.) That's $6 off and the best price we could find. It includes a dual USB charger and features a magnetic base and LCD display. Deal ends September 20.