07 Chevy Silverado aftermarket radio secuity question

[matrx10503]

Hello, I am debating on installing a new head unit in my 07 Silverado (no Bose)

Well I see that the [factory] radio has a red security light blinking.
I am wondering when I try to take it out and install the aftermarket, am I going to run into any security issues? If so, what will I have to do?
Also will I get to keep the "player keeps playing when cut truck off, until door opens" feature with the aftermarket?

[matrx10503]

nvm

To all: you must buy an expensive ($80-$100) adapter.

.....GM uses the speakers to play the door chime....SMH?!