i have a mazda 3 2005 , when i drive slow it squeaks super loud. any idea on what it could be guys ? and how i can fix it ?

 

The problem could be one of many potential issues. Please provide us as much detail as you can including engine size, type of transmission, where the noise is coming from, whether it changes proportional to engine speed or vehicle speed. You get the idea.

 

If it happens when your foot is on the brakes, then it's the brakes. Many times pads are installed without new brake hardware kit---then the hardware gets weak. Get new hardware. Even the rotors will develop a shine and squeak.
Click on the following reading mat'l for Brake issues:
TROUBLESHOOTING BASIC BRAKE PROBLEMS
How to Fix Squeaky Brakes: DIY Auto - Popular Mechanics
Brake Maintenance |*MotorWeek (Video)
Other possibilities: Fan belt, Fan belt tensioner, Bad pulley, wheel bearings.

 

Squeak or squeal?
Squeaks could come from the bushings on the suspension.
Squeals could come from the drive belts. In particular the one to the alternator.

 

Finally found my favorite Brake Video: Video: How to Diagnose a Brake Problem | eHow.com
They are driving around a Mazda as well!

Looking forward to Daytona 500 on Fox tonight , green flag @ 7:13 pm.

 

I too would like to know more before passing final judgement.
But I will say from my experience that if the sound is coming from the rear, and it happens when going over bumps, like speed bumps for example, it's likely going to be the rear sway bar bushings. An easy fix if that's it.
Go to your local plumbing supply house or Home Depot and ask for a small tub of silicone grease. Its going to cost you around $3- $3.50 but a little goes a long way. Raise the car up (and use jack stands, of course) remove the four 14mm nuts that hold the "C" brackets on. Slide them and the bushings aside, or remove them altogether, clean them and lube them up. Reinstall the "C" clamp bolts and torque to 55 ft. lbs.
It's a little easier if you also remove the center cover (a flat, square steel plate in the middle of the rear suspension) which is another 4 bolts, but its not necessary.