Has anyone had issues with the rear brakes popping or snapping off of the rotors once your 8 has sat for a couple days? I am assuming that the brake pads are adhering to the rotor due to damp conditions. Has anyone else experienced this as an issue?

If you mean the brakes make a clunking noise, then that's ABS system doing whatever it does at first as the car starts to roll. Mine does that the next morning when I'm backing out of the garage after the car just sits over night.

My car does it in the morning if I've set the e-brake. Feels like the pads are popping off the disc as I roll the car back. I don't drive aggressively on the street, so it isn't an issue of hot rotors. It hasn't affected performance of the car, brakes are still smooth at auto-x and on the track. My theory is that the moisture in the air is helping to oxidize the rotor and brake pad together and the pop is the tiny layer of oxidation between the rotor and pad breaking.

you could always try parking it in gear to avoid that as well.

There's nothing to "avoid"...it's perfectly normal. The car is designed this way so don't give it a second thought; enjoy your car. :)

Has anyone had issues with the rear brakes popping or snapping off of the rotors once your 8 has sat for a couple days? I am assuming that the brake pads are adhering to the rotor due to damp conditions. Has anyone else experienced this as an issue?
I know what you mean. If you live near the coast it will do this sometimes depending on the weather conditions. The pad and rotor essentially "rust" together. When you first move the car, there's an immediate popping sound (not the ABS check), then you might even hear a funky thunking sound as the wheel turns when you drive away until it's all gone. It's pretty normal. I avoid it by parking my car in the garage all the time, but sometimes if I leave my truck out overnight it will do that. I've never had any problems because of it. I always thought that it had to do with the big body of salt water off the coast because I never ran into this when I was a kid living much further inland.

hrm.. i've been wondering what that thunking sound was... i suspected it to be the abs.. but wasn't sure.. thanks

You can also get a 'clunk' if the brakes get wet and sit. There is just enough rust that will build up that it needs to release. Happens every time I wash the car and don't drive it until the next day.