I don't intend to thread jack, just didn't think it was necessary to make a whole new thread for this somewhat related question(s).
I personally am going to ditch my factory deck for an aftermarket one, as well as running new wires for everything - speakers, amps, etc. Is the factory stereo hole just an exact single DIN size? If I remember right the factory stereo has little screws on the sides that expand some tabs to hold it in. How do people get an aftermarket deck to stay in there snug, but still be able to remove it when needed?