Try this before get a new one... It works.....
I selectively copied the below from another GTO site (Thanks Wayne) and tryed the ON+4 trick and it made a difference to my ear
The major problem is that the Head Unit is sorta stupid. The EQ settings are
real dog crap, I honestly don't know what they were thinking. A stock GM unit
is better desgned. My Intrigue had a better HU. I won't ever buy Blaupunkt
after hearing these trashy EQs with reverb (and/or distortion), etc...
But, you can get around the problem if you just want the GTO to have a good
"natural" sounding stereo, and you like the music volume between 20 and 60 (on
1. Cut the radio off. Press the "On and 4" button for about 2 seconds. This
enables DDL and cuts of the EQ. Don't change anything. (See pages 3-46 and 3-47
of the manual if you're interested.)
2. Go in the trunk and cut up the subwoofer amp all the way. There's a sticky
thread... It takes 2 minutes. (Cut on the radio, pull down the carpet on the
left, and reach around to the know, and cut up the bass as loud as it will go.)
3. On the HU, set the bass to -2.
4. Set the trebel to -1
5. Put in your favorite CD and set it to about 45, and see what you think.
It's best to cut off the radio, and then hold down ON + 4 until the radio cuts
on. You get the perfect correct settings to start with...the factory settings
without the Blaush*t EQs.
ON + 4 for 2 seconds resets the HU to the defaults, which includes enabling the
DDL. You can cut it on or off with the display computer, or with the Options
menu on the HU. (ON + 1, Options).