By auto lock are you talking about the keychain or the button on the drivers door?
If neither works, thiers a Maxi fuse # 2 (It controls doorlocks,trunk release,
remote lock control.)under the hood,
and a fuse in the driverside fuse box #D .
If that doesnt work, the dealer will need to fix your lock cylinder.
When my wife bought our SE the trunk wouldnt unlock with the key either,
guess they adjusted the key tubbler, works fine now.
Migth try some WD40 in the lock, maybe its rusty/jamed.
I dont think you speaker box would mess with it unless it was sliding around and hit it hard a few times
