Patozon via Amazon offers the Mpow 6-amp 30-watt Dual USB Port Car Charger (pictured), model no. MC5-PTX-1, for $8.99. Coupon code "XASB5PSS" cuts it to $5.99. Plus, Prime members receive free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $6.98.) That's a buck under our March mention, $16 off, and the lowest total price we could find. It features two 3-amp ports and over-charging protection.
Also available is the Mpow 5.2-amp 26-watt Dual USB Portable Car Charger, model no. MC11-PTX-1, for $9.99. Coupon code "X9V7TGN8" cuts it to $6.99. With free shipping, that's $12 off and another price low. It features two 2.6-amp ports.