To be honest I need it but I don't buy it. The sign on my truck is broken. It's not cheap though, and the shop forgot to put the dust cover back on the front of my Subaru five years ago and you know what? Nothing has happened. Think about it, the front wheels get dirty too. Especially with alloy wheels, the rotors are completely open to the elements. And with a broken or missing dust cover you can easily monitor the condition of the rear of the rotor which can be a problem, I had two rear rotors for some reason and couldn't see with the shield installed.