Hi,
I just had the entry level AM/FM/CD player unit installed. I bought the HHR used and noticed that the cd player had some issues so got onto Ebay and bought a new higher end stock unit that did MP3 and has a 6 disc changer.
Since it was new,it didn't go into the lock mode and it works. No finally to my question.....I find that the radio doesn't seem to be as loud as the original. Is this perhaps due to the fact that it may be configured for the "premium" system and requires dealer intervention to have the unit "calibrated" to just the 4 speaker setup? Also notice that the signal light click is a lot lower but the chimes seem ok. Just don't want to waste my money on paying dealer if I don't have to.

Thanks in advance