So I have a 1990 s13 fastback and its make a high pitch noise when going over 23MPH. And it only happens when you step on the gas. But if you let off, it'll go away. But from the sounds of it, it sounds like its coming from the back of the car on both sides. Heres a Video.....Click on the picture.

You can hear the noise at the start of the video. Then I let off the gas. I pretty much go back and fourth. So what can it be?

You can hear the noise at the start of the video. Then I let off the gas. I pretty much go back and fourth. So what can it be?