My car makes a periodic noise as the wheel turns (around 25-70
miles/hour).  It's not metal creeking noise, but flapping sound.

Here are what some mechanics told me:

- One mechanic checked the car (lift it up and also do a drive test)
told me it is the brake rotor worn out not evenly.  However, when I
apply a slight push on the brake pedal, the noice is still there.  He
also notice that my left drive shaft is out of oil, and will need to be
replaced soon.

- A 2nd mechanic told me that it could be the ball bearing of the car,
and that needs to be replaced.  He asked me to tilt my head left and
right to hear where the noise is loudest, and where it fade, it seems
to be on the left.  However, it's not that definitive.  Also, drive
slowly from 5 to 10 miles/hour in a quiet area, there's also a clicking
noise on the right hand side (as the wheel turn).

- There's a 3rd mechanics (from the used car dealer that I bought the
car) that checked the car and said everything is tight, and safe to
drive, and old car makes noise.  However, I need to replace a steering
strut bearing because it makes noise when I turn the wheel (even when
the car not running).

So, the question is what's the source of the noise here?  Is it the
brake hitting the rotor?  Is it the wheel bearing?  Or is it the drive
shaft?

I wonder if I have any legal option to return the car or get it fixed
by the dealer.  It came with 30 days 50% power train warranty (which
already passed).  All the noise came during this time and I brought the
car in for those problem during that time.  The radio/CD player is not
working and they orally promise to replace it, but never deliver.

The 3rd mechanic/dealer refuse to pay for the cost of replacing the
steering strut bearing (he quotes around $270.00).  Initially, they
promised to fix it, but they keep putting grease on it and that noise
(from steering back and forth) went a way for couple days then came
back.  So, after 2 times of repair by greasing by them, the 3rd time I
brought the car in for repair, they looked at it, gave me a quote, and
refuse to pay for it. (they said it's a courtesy thing to replace the
radio and the repair, but they're not willing to pay for a new radio or
the replace of the bearing).