I'm really not sure if this is a problem or not but figured I'd ask.

My rear brake pads stick to the discs after the parking brake has been applied. When I go out in the morning after the car sitting all night I can hear/feel the brake pads separate from the discs when I move, they don't release when I release the parking brake.

I live in Canada, so it's like 10 or so degrees or below freezing nightly and it's pretty wet/icy out.

Is this problem common? Should I be concerned? ... The discs themselves still don't have a groove in them but I did notice there seems to be a bit of a ridge right at the edge of the disc.

 

Ehhhh, mine does the same. Sounds like crap on the first application of the brakes, real deep groan if you are backing up at the time. No real noise after that.

I chalk it up to the cheap ass cast they used for the discs, they literally rust over night and the pads stick

A little lip at the edge is normal wear, the pads don't go quite to the edge of the disc.

I wouldn't loose any sleep, mine has been doing this since new ("They all do that" was the dealers response) and I am just hitting 100k km - rear brakes are less than half gone......