Amazon takes up to $30 off ($15 for front, $15 for rear) a selection of Wagner ThermoQuiet brake pads via this mail-in rebate, dropping starting prices to $0. Plus, Prime members receive free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, it starts around $5.) That's a strong deal putting many models at an all-time low. Rebate expires May 31.