Very annoying squeak!
 

I have a 2010 Mazda3 i touring sedan with almost 60K on it and have the most terrible squeak coming from inside the back seat area or trunk. I have taken everything out of the trunk thinking it was the foam tool holder but its still there. The squeak does not go away and you hear it the whole time you are driving. Short of getting rid of the car which I do not want to do I don't know what to do to get rid of it. Any help would be great!

In order to diagnose a problem like this, I would grab a buddy to get in the back and listen around. Try to pin point the area of which the sound is coming from, while trying to replicate the conditions in which it does this squeak.

Usually squeaks will come from metal on metal parts, dry rubber bushings on metal, or worn suspension parts, ie: struts, coil spring end insulation wear and metal on metal coil into cup,ball joints, sway bar end links/ bushings. etc.

Test the suspension components lightly by firmly pulling and monitoring with a light the play within these regions. Look for signs of wear like metal on metal or rust/ corrosion.

If you think you have pinpointed the component and aren't sure, then spray the spot somewhat generously with pb blaster, wd-40, or what what we like to call (weezle piss). This should make the friction go away and cause it to be quieter or go away temporarily.

Hope that helps! Let us know what you find.

- JohnO.

Thanks, as of now I am fairly sure its coming from the plastic in the rear window area or the rear window its self. My plan is to do just what you suggested and have someone ride in the back and try to find it. Thanks for the suggestions and I will let you know how it goes.

My wife drives a 2010 Mazda 3 sedan and she had me sitting in the back while she drove around earlier today trying to find out where that aggravating squeak comes from. I first thought it was from the back dash but ultimately, it seems to be coming from somewhere in the back of the headliner. The only way to get the squeak to stop was to push up on the headliner itself. I still have to pinpoint the sound and then figure out how to stop it. If you figure it out... let us all know!

I read somewhere that this squeak might be related to some alignment tabs attached to the rear glass under the headliner. Apparently they get sometimes rub against metal and squeak. You can either try to lubricate them or remove them (they indicated that they are not required once the glass is properly set) to solve the squeak. I am waiting for it to get a little warmer outside before I go looking for these tabs. I'll let you know what I find.

The noise as of right now has been solved! It turns out it was not coming from the rear of the car but it was the transmission mounts, they among other areas under the car had collected a large amount of gravel from my steep driveway. I took the car to the dealer thinking it had a transmission problem since the car would vibrate and make odd noises only when cold and only in reverse. $85 later the problem seems to be fixed, now on to the cruise control light that randomly comes on when starting the car!

Backseat
 

I have a 2012 Mazda3 sedan and I had the same problem and I took my car to the dealership and they had to replace foam pieces under the back seat. No more squeak.

I will have to look into that, my squeak came back when it turned cold again. Its coming from the read of the car and I thought it was the seat or rear window.