So. I bought a Monte Carlo. 2006 SS.
Radio is Locked....
What are my options?
Radio is the stock one as well...
Wanna get this bad boy unlocked...
Also. The blinker sound doesn't work on my car. Is that related to this issue?

 

Dealership will have to unlock it for you. Might be that they had an aftermarket set up, and switched back to stock afterwards but messed up, or didn't use the factory radio they removed.

Blinker might need a radio module, but I'm not sure. If you leave the keys in the ignition and open the door, do you hear the audible beep from the front left speaker? That speaker is known to go bad on a 7th gen. Just another thing to check.

 

Other option would be to get another aftermarket unit.

The blinker sound is dependant on the factory radio or a reasonable facsimile thereof.

There could be more things disconnected down the line like an amplifier in the trunk under the package shelf.

 

There is no stock amplifier in the 7th gen. Wouldn't surprise me if there were an issue back there, if there were mods. In my Aurora, the previous owner had somehow involved the wiring for the trunk light with the speaker wiring. The speakers were lovely, but I had no trunk light. (And you guys wonder why I'm so anti-mod.)

Second the motion on an unlocked replacement head unit. I got one for the wife's SRX for $45 on eBay. It was actually an improvement over the original, whose clock didn't work.