I just found this online
Now, here's the hack:
1. (involved pulling headunit from dash)
2. Remove the four tiny screws on the face plate of the headunit.
a. You will need to slide the sleeve to the rear of the headunit.
3. Remove the silver sticker that is on the bottom of the unit. Congratulations. You have voided your warranty.
4. Now that the sticker is removed, you will see a black switch. With a small (really small) bladed screwdriver, slide the little switch to the left.
5. Next, you'll need to ground the light green parking brake wire to a negative wire on the