unitek-eshop via Ebay has Unitek 3-Port USB Aluminium 4.8A Smart Car Charger for $4.94 with free shipping, you can save $8.05 at checkout.

Features include:

• USB multi-port car charger enables you to charge cell phone and tablet while driving.
• With 12-24V power input, supports up to 2.4A power output.
• 3.6V-5V2A / 5.2V-9V2A / 9.2V-12V1.5A.
• The QC3.0 charging port will auto detect the devices which support QC3.0
• Protection against over-charging, over-voltage, over-heating and short circuit.
• Total power output up to 42W.