Static from stock radio

[sourmash]

I was wondering if someone familiar with car audio can tell me what is going on with the stereo in my car.
There is a lot of background static (a "ssssssssssss" or "ppppssssssssspssssspsss" sound) when I turn on the radio...even before I hear the sound of music from the station. The sound is intermitent...some days its constant, some days it barely happens. The stations I listen to are pretty powerful, so its not like I'm going in and out of reception...and this does not occur in any of our other cars.
The sound doesn't (always) occur when playing a cd from the trunk mounted changer...but is usually there when first turn it on before the music plays.
I'm doubtful it's a blown speaker...because when it does play clear with a CD, it is loud and clear.
Also, a few times when I've turned on the unit the radio will be loud (not how it was left) and when I try to turn the volume down it doesn't work. I then push in the power button and push it again to turn it back on...and everything goes back to normal.

Can anyone help me figure out what is going on. My father-in-law thinks the speakers need to be replaced...but for some reason I don't think it's the speakers...but probably the head unit itself.

[Jeremy Toaster]

I get a lot of electrical engine noise coming through my stereo, when I accelerate, I can hear it whining in the speakers. Also now that I have a PIE interface device that intercepts my CD changer to allow my iPod to run through, I get lots of stereo noise when the iPod is also plugged into the cigarette outlet for charging while playing, if I unplug the charger it goes down, also sometimes I just get noise and if I power off and on the stereo once, it cuts out for a while.

http://www.crutchfield.com/S-KX2ZRQ5...1150&I=003S25A

What thinking about getting something like this? Does anyone have any electric noise reducers installed in their car?