yes i have and if it is a avh-????dvd it is easily bypassed (not just grounded) but switched ground .......can be done with relay or just a simple toggle switch (one end to ground and other to parking brake lead)the avic (navigation units) like the Z130bt or Z1140 bh or X930bt or X940bh require a moving a pin in a/v harness and grounding it along with the parking brake wire.
but to answer the Question you asked the parking brake wire is located @ the lever under the center console / while there is nothing published on the wire itself , it will be very easy to locate,, on the base of the lever there will be a wire (connected to a pin ) that goes to ground when the brake is engaged. (it must go to ground) just use that and "viola'" you are hooked up "legal"
good luck