tire or rotor?

on my 2000 buick regal, i have developed a type of slap. it sounds like its coming from the rear, but im not positive. i changed the brake pads 3 months ago, but not the rotors, i drive it up and down my driveway[180 ft long] no noise. put it on the road and it sounds like i have a flat tire, but i dont. someone said the rotors and someone else said i have a bad tire somewhere, broken treads or something. we put it on the lift at wal-mart and they found nothing. but they wasnt really looking. we balanced the tires and the slap is still there. how can i tell what is wrong?? thanks
bill

on my 2000 buick regal, i have developed a type of slap. it sounds like its coming from the rear, but im not positive. i changed the brake pads 3 months ago, but not the rotors, i drive it up and down my driveway[180 ft long] no noise. put it on the road and it sounds like i have a flat tire, but i dont. someone said the rotors and someone else said i have a bad tire somewhere, broken treads or something. we put it on the lift at wal-mart and they found nothing. but they wasnt really looking. we balanced the tires and the slap is still there. how can i tell what is wrong?? thanks
bill it makes no difference in the sound when i hit the brakes,

I would bet it's either a bad tie rod, bad control arm bushing or a bad hub bearing.

it sounds as if its coming from the rear. i just had a tie rod put on the front a few weeks ago. thanks
bill

it sounds as if its coming from the rear. i just had a tie rod put on the front a few weeks ago. thanks
bill
the noise definately appears to be coming from drivers side rear. roll the front window down and you cant hear it , roll the back glass down and you can hear it good, sounds like a flat. i switched the rear tire to the front and it made no difference. the noise is still in the rear. i had new pads put on the rear a few weeks ago but he didnt do anything to the rotors. running me wacky- doo. lol thanks for any ideas.
bill

Forget the brake pads and rotors. It sounds like you have something loose or broken. Check the rear sway bar, the rear strut or even the exhaust system. There is also a possibility that the noise is coming from the parking brake so check that too. As richtazz said don't rule out a rear bearing.

Just a thought and the 2000 may not have the leaf spring, but mine makes that noise and is caused by a missing insulator on the end of the leaf which bangs off the bottom of the strut.