For its newsletter subscribers only, EverydaySource offers this Universal FM Transmitter with Remote for $17.99. Coupon code "S0609MCCY" cuts it to $7.29. With free shipping, that's the lowest total price we could find for this type of transmitter by $1. It connects to any audio device with a 3.5mm jack and can tune to any unused FM frequency. It also features USB connectivity and an SD card slot, allowing you to play MP3s dirtectly from the transmitter. Coupon expires after 1,000 uses.