AnkerDirect via Amazon offers the Anker 40-Watt 5-Port USB Car Charger in Black or White, model no. AK-71AN7104C, for $19.99. Coupon code "6DOF7104" cuts it to $13.99. Plus, Prime members receive free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping adds $6.29.) That's $26 off list and the lowest price we could find. It features Power IQ technology and is compatible with most USB-powered devices.