Yes it is possible, though it may take some technical skill. One of the easiest (and possibly only) ways of doing this is to install CoastalTech's Ultimate Lockpick 3+ (http://www.coastaletech.com/lockpick3.htm). The UL3+ is the most expensive lockpick at $299.00, but with all the features it unlocks and the apparently easy installation (from what I've read on forums), this price tag is not too much to ask for the benefits:
UNLOCK VIDEO AND AUDIO INPUT, REMOVE "I AGREE" MESSAGE, UNLOCK BLUETOOTH ENTRY,
INPUT ADDRESSES WHILE IN MOTION.
Once you install this mod you will have composite A/V cables dangling from somewhere. With a bit of engineering you should be able to route the cables intot eh back of the CD bay below the radio, install a portable DVD player into the CD bay and possibly even still be able to shut the door to hide it :) (or you could put the DVD player and/or any A/V hookup device anywhere in the car, this method just seems to be the most professional looking imho) Also, some portable DVD players have A/V input on the front which would allow you to hook up an iPod/iPhone* giving you support for DVD playback AS WELL AS any media on your portable device.
*for classic, itouch, and iPhone you must buy the proprietary cable for A/V out from apple because it has a chip inside that the portable device checks for (shady on apple's part but necessary nonetheless)
The 2007 Toyota Prius has 16 valves.
The 2007 Toyota Prius is a hybrid-powered vehicle.
The 2007 Toyota Prius has an inline 4 engine.
A 2007 Toyota Prius has 4 spark plugs.
The 2007 Toyota Prius runs on regular unleaded.
The height of the 2007 Toyota Prius is 4 ft. 10.7 in. (58.7 in.).
The 2007 Toyota Prius has a continuously variable-speed automatic.
The 2007 Toyota Prius has double overhead cam (DOHC).
The curb weight of the 2007 Toyota Prius is 2932 lbs..
The 2007 Toyota Prius is 14 ft. 7 in. (175 in.) long.
The 2007 Toyota Prius has a drag coefficient of .26 Cd.
The 2007 Toyota Prius has 52.9 in. of rear shoulder room.
The 2007 Toyota Prius has 55.0 in. of front shoulder room.
The 2007 Toyota Prius has 51.0 in. of front hip room.
The 2007 Toyota Prius has 38.6 in. of rear leg room.
The 2007 Toyota Prius has 51.6 in. of rear hip room.
The 2007 Toyota Prius has 39.1 in. of front head room.
The 2007 Toyota Prius has 41.9 in. of front leg room.
The 2007 Toyota Prius has 37.3 in. of rear head room.
The rear track of the 2007 Toyota Prius is 4 ft. 10.3 in. (58.3 in.).
The ground clearance of the 2007 Toyota Prius is 0 ft. 5.6 in. (5.6 in.).
The 2007 Toyota Prius has a 8 ft. 10.3 in. (106.3 in.) wheel base.
The 2007 Toyota Prius has a 1.5 L base engine size.
The drivetrain warranty of the 2007 Toyota Prius is 5 yr./ 60000 mi..
The 2007 Toyota Prius has a 3 yr./ 36000 mi. basic warranty.