Betdaq Direct via Amazon offers the Tycipy Car Humidifier / Essential Oil Diffuser in Black, Blue, or White, model no. BE-CH-II, for $16.99. Coupon code "DOSFS33A" drops it to $8.49. Plus, Prime members bag free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $6.70.) That's a slight drop from our November mention and a buck less than you'd pay for a similar item elsewhere. It plugs into your car's DC port and features a 1.7-oz. water tank that rotates 180°, ultrasonic atomization technology, two USB charging ports, and automatic shutoff. Deal ends March 30.