Aukey via Amazon offers the Aukey Rapid Dual USB Car Charger in Black or White, model no. MK347, for $9.99. Coupon code "2L6RMF8Q" cuts it to $5.99. Plus, Prime members bag free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, it adds $6.01.) That's tied with our mention from last summer and the lowest total price we could find by $8. It features 4.2 amps of power and is compatible with most USB-charged devices.