For setting this up to view DVD's while driving (bypass safety lock-out), you'll need to get a standard 5-wire automotive relay and wire it up per these instructions:

1. connect "30" to the parking brake wire from the headunit
2. connect both "86" and "87" to ground
3. connect "85" to the remote turn-on wire from the headunit

What this does is send a pulse to the headunit to trick it into thinking you've turned on the parking brake. If you simply connect the parking brake wire to ground only, it will not work.

The DVD, CD, Radio, Ipod, and Bluetooth functionality on this headunit are all great! The touchscreen is very responsive too. One of the best features is the ability to change both the external buttons and the on-screen display (OSD) colors to match your factory interior gauge lighting. My 2008 Subaru STI comes with all red interior lighting so I selected the AVH-P4000DVD to have red buttons and red OSD.

PROS:
- Ipod controls w/ CD-I200 are amazing: mimics real Ipod controls on the screen (Except for scroll wheel), responsive, and charges Ipod while docked
- Bluetooth Module (CD-BTB200) works well as long as you update the software of your phone (I needed a software update on my Blackberry Pearl 8100 to get it to work properly)
- External Volume knob, very helpful
- Clear 6.5" screen, dims when headlights are on for night viewing
- Touchscreen very accurate and responsive
- External button and OSD screen colors can be customized to any interior (Red, Blue, Green, Orange, Violet) for factory look
- DVD playback is great
- Easy to use interface

CONS:
- only 2 pairs of preouts (front and rear/subwoofer)
- No navigation, but that is why its so cheap
- No remote control comes standard (optional CD-R55)

Conclusion:
Just get it. You'll love it.