Amazon is selling the Motorola Rapid car charger for $4.23. Compatible with 4g and any cell phone with microusb. I have one for every car because it is such a great deal.
Amazon.com: Motorola Vehicle Power Adapter micro-USB Rapid Rate Charger: Cell Phones & Accessories
Amazon.com: Motorola Vehicle Power Adapter micro-USB Rapid Rate Charger: Cell Phones & Accessories