Well, i don't have a snazzy stock system, but i do have an Alpine in-dash one that does the same thing. I have been trying to figure out how to bypass that safety issue as well.... I did a google search for "alpine dvd without parking brake" and it brought up a bunch of results that looked promising... however, i don't understand any of that electronic mumbo-jumbo so i am going to have my fiancé look at it haha. I would assume that those techniques they are using on the Alpines would also work for the stock system. Sorry i don't have a better answer... good luck!