I just purchased the N4 on Crutchfield and installed the unit. I installed everything exactly how it was suppsoed trying not to do any changes and just get the thing in and working. I spoke to someone at Car Toys and was told that the N4 has a "special" gyro in it and even if you ground out the parking brake bypass it will not work while you run. Is that even what you do is ground the parking brake lead? Please tell me how I would go about changing this as DVD is not the only feature disabled while driving. I noticed many features auto disable as soon as my parking brake is released. Thank you so much in advance.

There is a thread about ten below this one called AVICN4 Bypass. You should read it

It is now stickied, as requested, and, obviously, needed.